MYL1 exists as two splice variants:
MLC1F: Expressed in embryonic, fetal, and adult fast skeletal muscle.
MLC3F: Upregulated during fetal development and maintained in adult fast skeletal muscle .
Property | Value | Source |
---|---|---|
Molecular Weight | 25 kDa (recombinant) | |
Chromosomal Location | 2q32.1-qter | |
Recombinant Expression | E. coli (N-terminal GST-tagged) | |
Purity | >90% (SDS-PAGE) |
MYL1 binds to the IQ domain of myosin heavy chains (MHCs), stabilizing the myosin-actin interaction. While it does not bind calcium directly, it facilitates structural integrity and force generation in myofibrils .
Key Functional Partners (from STRING interaction network ):
Protein | Interaction Score | Role in Muscle Function |
---|---|---|
MYH7 (Myosin-7) | 0.998 | Forms thick filaments for contraction |
MYLPF (pMyosin) | 0.995 | Phosphorylatable regulatory light chain |
TNNI2 (Troponin I) | 0.973 | Calcium-sensitive thin filament control |
NEB (Nebulin) | 0.973 | Sarcomere structural maintenance |
Survival Analysis (from Sage Journals ):
Group | MYL1 Expression | Survival Outcome |
---|---|---|
Rhabdomyosarcoma | High | Poor OS |
Healthy Controls | Low | Not applicable |
Bi-allelic MYL1 mutations cause severe myopathy:
Recombinant MYL1 is produced in E. coli for research and diagnostic purposes:
Parameter | Recombinant MYL1 | Source |
---|---|---|
Formulation | 10 mM Tris-HCl, 1 mM EDTA, pH 7.5 | |
Stability | -20°C to -80°C (12 months) | |
Biological Activity | Not tested |
MYL1 is a gene that encodes the Myosin Light Chain 1 protein, a critical component of the contractile apparatus in skeletal muscle. This protein plays an essential role in muscle contraction by interacting with myosin heavy chains to facilitate proper sarcomere function. In normal physiology, MYL1 contributes to the structural constituents of muscles and participates in regulating muscle differentiation and function . MYL1 has been identified as an early marker of rapid muscle cell differentiation, as evidenced by studies in zebrafish where it was shown to be involved in muscle fiber differentiation . The protein is primarily expressed in skeletal muscle tissues, where it contributes to the functional integrity of the contractile machinery. Understanding MYL1's normal physiological function provides crucial context for investigating its role in pathological conditions.
Researchers typically employ multiple complementary methodologies to distinguish normal from aberrant MYL1 expression. Quantitative reverse transcription PCR (RT-qPCR) serves as a primary technique for comparing MYL1 transcript levels between healthy and diseased tissues. This approach allows for precise quantification of expression differences, as demonstrated in studies comparing rhabdomyosarcoma tumor tissues with healthy controls . Additionally, researchers utilize immunohistochemical staining to visualize MYL1 protein localization and abundance in tissue sections, which can reveal both expression level differences and potential alterations in subcellular distribution.
For more comprehensive analyses, researchers often employ bioinformatics approaches to analyze large-scale gene expression datasets. This might include mining data from resources like The Cancer Genome Atlas (TCGA) and comparing expression profiles across various tissue types and disease states . These comparative analyses can identify statistically significant expression differences and correlate them with clinical parameters such as disease progression and patient outcomes. Careful selection of appropriate control tissues and standardization of experimental protocols are essential for meaningful interpretation of expression differences.
Multiple experimental models have been developed to investigate MYL1 function across different research contexts. In vitro systems include primary human myoblast cultures that can be differentiated into myotubes under defined conditions, providing a controlled environment to study MYL1 expression during muscle differentiation . Such in vitro models are particularly valuable for studying molecular mechanisms and conducting high-throughput screening experiments.
Animal models, including zebrafish, have proven particularly useful for studying MYL1's role in muscle development and differentiation in vivo . The transparency of zebrafish embryos enables real-time visualization of muscle development, while their genetic tractability facilitates manipulation of MYL1 expression. Mouse models have also been employed to study MYL1 function in the context of aging and muscle pathology, with single-myofiber RNA-Seq analysis revealing age-related alterations in MYL1 expression .
For translational research, human tissue samples remain invaluable. Studies have employed both fresh and archived human muscle tissues to examine MYL1 expression in various pathological conditions, including rhabdomyosarcoma . The integration of findings across these complementary model systems provides the most comprehensive understanding of MYL1 biology.
Substantial evidence from multiple analytical approaches has established MYL1 as a significant biomarker in rhabdomyosarcoma. Differential gene expression analyses comparing rhabdomyosarcoma tumor samples with healthy control tissues have consistently identified MYL1 as significantly upregulated in the cancerous state . This finding has been validated through both bioinformatics analyses of large datasets and direct experimental verification using RT-qPCR in patient samples. The consistency of MYL1 upregulation across different patient cohorts and analytical platforms strengthens its potential utility as a diagnostic biomarker.
Furthermore, when researchers constructed protein-protein interaction (PPI) networks to identify hub genes relevant to rhabdomyosarcoma pathogenesis, MYL1 emerged as one of the key players in the disease network . Functional annotation analyses have linked MYL1 to biological processes and pathways that are dysregulated in rhabdomyosarcoma, providing mechanistic plausibility for its role as a biomarker. These converging lines of evidence from genomic, transcriptomic, and functional studies collectively support MYL1's significance in rhabdomyosarcoma diagnosis and potentially in monitoring disease progression.
The survival correlation has been validated across multiple patient cohorts, including through analyses of data from The Cancer Genome Atlas (TCGA) and through direct RT-qPCR verification in clinical samples . This consistent relationship between elevated MYL1 expression and poor prognosis reinforces its potential clinical utility. The specific survival data shows a clear stratification of survival curves, with the high-MYL1-expression group demonstrating markedly worse outcomes. This relationship holds even when controlling for other clinical variables, suggesting MYL1 may provide independent prognostic information that could influence treatment decisions and patient management strategies.
Several molecular mechanisms have been proposed to explain MYL1's potential role in rhabdomyosarcoma pathogenesis, though the precise pathways remain under investigation. As a component of the muscular contractile apparatus, aberrant MYL1 expression may disrupt normal myogenic differentiation processes, potentially contributing to the abnormal muscle cell phenotype characteristic of rhabdomyosarcoma . The protein's involvement in regulating muscle contraction, growth, and metabolism suggests multiple potential points of impact on cancer cell behavior.
Research indicates that MYL1 may participate in pathogenesis by maintaining the structural components of muscle while simultaneously affecting differentiation pathways . This dual role could promote a state where cells retain muscle-like characteristics but escape normal differentiation controls. Additionally, MYL1 has been implicated in metabolic regulation, which may provide rhabdomyosarcoma cells with altered energetic capabilities supporting their malignant growth .
Interestingly, MYL1 dysregulation appears to occur alongside other known oncogenic factors in rhabdomyosarcoma. For instance, studies have noted relationships between MYL1 expression and established markers like MyoD1 and myogenin, which are known to correlate with rhabdomyosarcoma prognosis . This suggests MYL1 may be part of a broader dysregulated network of muscle-specific factors contributing to the disease's development and progression.
Beyond rhabdomyosarcoma, MYL1 dysregulation has been implicated in several other pathological conditions. Research has identified abnormal MYL1 expression or function in congenital myopathy, where structural and functional abnormalities of myosin can lead to muscle weakness and developmental issues . Molecular analyses suggest that MYL1 abnormalities may cause structural changes in myosin that contribute to the disease phenotype, making it a potential diagnostic marker and therapeutic target for this condition.
Studies have also linked MYL1 to degenerative joint diseases, where it may participate in disease development by affecting normal muscle functioning around joints . The gene has further been associated with steroid-induced necrosis of the femoral head, suggesting its involvement in maintaining normal muscle function necessary for proper skeletal support and preservation of joint integrity .
Additionally, bioinformatics analyses have identified elevated MYL1 expression in prostate cancer patients. Researchers propose that in this context, MYL1 may influence disease progression by regulating muscle contraction, growth, and metabolism pathways that become co-opted in the malignant state . These diverse pathological associations highlight MYL1's multifaceted roles in human physiology and pathophysiology, spanning both muscular and non-muscular disorders.
Research investigating age-related changes in muscle has revealed significant alterations in MYL1 expression and function throughout the aging process. Using sophisticated single-myofiber RNA-Seq analysis approaches, researchers have documented abnormal expression patterns of MYL1 in the muscle fibers of aged mice compared to younger animals . These expression changes appear to correlate with the well-documented decline in muscle mass, strength, and function observed in aging populations.
The alterations in MYL1 expression may contribute to age-associated muscle dysfunction through multiple mechanisms. Evidence suggests that normal MYL1 function may help stabilize muscle fiber structure and regulate metabolic processes essential for optimal muscle performance . Age-related disruption of these functions could therefore contribute to sarcopenia and frailty. Understanding these changes becomes increasingly important in the context of an aging global population, as they may represent potential intervention points for preserving muscle function in older adults.
Interestingly, the age-related changes in MYL1 expression appear to be fiber-type specific, potentially explaining some of the differential susceptibility of various muscle groups to age-related decline. These findings highlight the complexity of MYL1 regulation across the lifespan and suggest that therapeutic approaches may need to account for age-specific alterations in expression patterns and functional requirements.
Multiple lines of evidence suggest MYL1 may represent a promising therapeutic target across several pathological conditions. In rhabdomyosarcoma, the strong correlation between MYL1 overexpression and poor patient outcomes provides a compelling rationale for exploring interventions that normalize its expression or function . The consistency of this relationship across multiple patient cohorts strengthens the case for MYL1-targeted therapeutic development.
In congenital myopathy, research has identified MYL1 abnormalities as potentially causative factors in disease pathogenesis, suggesting that correcting these abnormalities might ameliorate disease symptoms . Similarly, in degenerative joint conditions and steroid-induced femoral head necrosis, MYL1's role in maintaining normal muscle function positions it as a potential target for preventing disease progression .
From a mechanistic perspective, MYL1's involvement in fundamental processes like muscle differentiation, contraction, and metabolism provides multiple potential intervention points. Therapeutic approaches could target MYL1 expression levels, protein-protein interactions, or downstream signaling pathways. The diverse pathological conditions associated with MYL1 dysregulation further suggest that successful therapeutic strategies might have broad applicability across multiple diseases, increasing their potential clinical impact and commercial viability.
Several sophisticated bioinformatics approaches have proven particularly effective in advancing our understanding of MYL1 biology and its role in disease. Differential gene expression analysis comparing disease states (such as rhabdomyosarcoma) with healthy controls has successfully identified MYL1 as a significantly dysregulated gene across multiple datasets . These analyses typically involve normalizing raw expression data, applying statistical tests to identify significant differences, and implementing correction methods for multiple testing.
Protein-protein interaction (PPI) network construction has been instrumental in contextualizing MYL1's role within broader biological systems. By analyzing the network topology and identifying hub genes, researchers have positioned MYL1 within functional modules relevant to disease pathogenesis . This network-based approach provides insights into potential interaction partners and downstream effectors that might mediate MYL1's biological functions.
Survival analysis methods, particularly Kaplan-Meier curves with log-rank tests, have established significant correlations between MYL1 expression levels and patient outcomes . These statistical approaches allow researchers to determine whether MYL1 expression has prognostic significance and to quantify the strength of this relationship. Additionally, gene ontology (GO) and pathway enrichment analyses have helped elucidate the biological processes and signaling pathways associated with MYL1, providing mechanistic context for its role in normal physiology and disease .
Accurate measurement and validation of MYL1 expression requires a multi-modal approach combining complementary techniques. RT-qPCR represents the gold standard for quantifying MYL1 transcript levels, offering high sensitivity and specificity when performed with carefully designed primers and appropriate reference genes . For optimal results, researchers should adhere to MIQE (Minimum Information for Publication of Quantitative Real-Time PCR Experiments) guidelines, which standardize experimental design, validation, and reporting.
Western blotting provides information about MYL1 protein levels and can reveal post-translational modifications that may affect function. When performing Western blots, researchers should include appropriate loading controls and validate antibody specificity to ensure reliable results. Immunohistochemistry offers valuable insights into MYL1's tissue distribution and subcellular localization, complementing quantitative expression data with spatial information .
For comprehensive validation, researchers should combine these methodologies with in silico analyses of publicly available datasets. Tools like GEPIA (Gene Expression Profiling Interactive Analysis) and databases such as TCGA (The Cancer Genome Atlas) provide valuable independent validation cohorts . The integration of findings across multiple experimental platforms and patient cohorts strengthens confidence in observed expression patterns and their biological or clinical significance.
Cutting-edge experimental approaches are significantly expanding our understanding of MYL1's functional roles in both normal physiology and disease states. Engineered in vitro systems utilizing primary human myoblasts cultured under defined conditions provide controlled environments for studying MYL1 during muscle differentiation . These systems can be modified to include specific growth factors like IGF1 that promote more physiologically relevant myotube formation, enabling more accurate assessment of MYL1's function in a muscle-like context.
CRISPR-Cas9 gene editing technologies offer unprecedented precision for manipulating MYL1 expression or creating specific mutations that mirror those found in patient samples. This approach allows researchers to establish direct causality between genetic alterations and phenotypic outcomes. When combined with inducible expression systems, these tools enable temporal control over MYL1 manipulation, facilitating the study of its role during specific developmental or disease stages.
Single-cell RNA sequencing represents another transformative approach, allowing researchers to examine MYL1 expression heterogeneity within tissues at unprecedented resolution. This technique has been particularly valuable in aging studies, where it revealed cell-type specific alterations in MYL1 expression that were previously masked in bulk tissue analyses . Additionally, advanced imaging techniques combined with electrical stimulation protocols are enabling real-time visualization of MYL1's role in muscle contraction, providing functional insights beyond static expression data .
Designing rigorous controls is essential for generating reliable and interpretable data in MYL1 research. For gene expression studies, researchers must include appropriate tissue-matched controls that account for the muscle-specific expression pattern of MYL1. When studying disease states like rhabdomyosarcoma, matched non-malignant muscle tissue from the same anatomical location provides the most relevant comparison . Additionally, researchers should consider including positive controls with known high MYL1 expression (such as skeletal muscle) and negative controls with minimal expression (such as non-muscle tissues) to validate assay performance.
For functional studies investigating MYL1's role in processes like muscle differentiation, temporal controls are crucial. Time-course experiments with multiple sampling points can reveal dynamic changes in MYL1 expression and function throughout the differentiation process . When manipulating MYL1 expression experimentally, both gain-of-function and loss-of-function approaches should ideally be employed to provide complementary evidence for its role.
Technical controls must also be carefully considered. For RT-qPCR analyses, multiple reference genes should be validated for stability in the specific experimental context, rather than relying on single "housekeeping" genes that may vary across conditions . Similarly, for protein-level analyses, appropriate loading controls and antibody validation are essential. These comprehensive control strategies ensure that observed changes in MYL1 expression or function can be confidently attributed to the biological phenomenon under investigation rather than technical artifacts.
Contradictory findings regarding MYL1 function across different experimental models require systematic analytical approaches to resolve. First, researchers should carefully evaluate the biological context of each model, as MYL1's function may be genuinely different in various tissues, developmental stages, or disease states. The specific muscle fiber type composition can significantly influence MYL1 expression patterns and function, potentially explaining apparently contradictory results between models with different fiber type distributions .
Methodological differences often underlie apparent contradictions. Researchers should scrutinize experimental protocols, including cell culture conditions, sample preparation techniques, and analytical methods. For instance, in vitro myotube models may yield different results depending on the differentiation protocol used, as factors like IGF1 supplementation can dramatically alter the physiological relevance of the model . Similarly, different antibodies used for protein detection may have varying specificities or recognize different isoforms of MYL1.
When contradictions persist despite careful methodological analysis, integration of multiple complementary approaches becomes essential. Combining in vitro studies with animal models and human tissue analyses can provide a more comprehensive understanding that reconciles apparent contradictions . Meta-analysis of multiple independent studies can also help identify consistent findings amid seemingly contradictory results. Finally, researchers should consider publishing negative or contradictory results alongside positive findings to build a more complete picture of MYL1 biology and prevent publication bias.
Analyzing MYL1 expression in clinical samples requires robust statistical approaches that account for biological variability and potential confounding factors. For comparing expression between groups (e.g., tumor vs. healthy tissue), parametric tests like t-tests or ANOVA may be appropriate if data meet normality assumptions; otherwise, non-parametric alternatives such as Mann-Whitney U or Kruskal-Wallis tests should be employed . Given the potential for multiple testing when analyzing gene expression data, appropriate correction methods (e.g., Benjamini-Hochberg procedure) should be applied to control false discovery rates.
For survival analyses, Kaplan-Meier curves with log-rank tests provide a visual and statistical assessment of MYL1's prognostic significance . Cox proportional hazards regression enables multivariate analysis that can determine whether MYL1 expression provides independent prognostic information beyond established clinical factors. When defining "high" versus "low" expression groups, researchers should employ objective methods such as median split or optimal cutpoint algorithms rather than arbitrary thresholds.
Power analysis should be conducted during study design to ensure sufficient sample sizes for detecting biologically meaningful differences in MYL1 expression. This is particularly important in clinical studies where sample availability may be limited. Furthermore, validation in independent cohorts is essential for confirming the robustness of findings. Data visualization techniques, including box plots for group comparisons and forest plots for multivariate analyses, enhance the interpretability of statistical results and facilitate communication of complex findings.
Several promising research directions are poised to significantly advance our understanding of MYL1 biology and its clinical applications. Single-cell analysis technologies offer unprecedented resolution for examining MYL1 expression heterogeneity within tissues, potentially revealing specialized functions in specific muscle fiber subtypes or identifying rare cell populations with distinctive MYL1 expression patterns . This approach could uncover previously unrecognized roles for MYL1 in muscle physiology and disease.
Mechanistic studies exploring the specific signaling pathways through which MYL1 influences muscle differentiation, contraction, and metabolism represent another high-priority area. Understanding these molecular mechanisms could reveal potential intervention points for therapeutic development across multiple MYL1-associated pathologies . Particular attention should be given to MYL1's interactions with other muscle-specific factors known to be involved in rhabdomyosarcoma pathogenesis, such as MyoD1 and myogenin .
Translational research exploring MYL1 as a biomarker or therapeutic target in well-defined patient populations holds significant promise. Prospective clinical studies examining MYL1 expression in relation to treatment response and disease progression could establish its utility in personalized medicine approaches . Additionally, developmental studies investigating MYL1's role in muscle formation and maturation could provide insights relevant to regenerative medicine applications, particularly in conditions involving muscle degeneration or injury.
Emerging tissue engineering approaches offer transformative potential for MYL1 research by providing more physiologically relevant experimental systems. Advanced in vitro muscle models that better recapitulate the three-dimensional architecture and functional properties of native muscle tissue enable more accurate investigation of MYL1's role in muscle development and contraction . These engineered tissues can be specifically designed to facilitate electrical stimulation, allowing real-time assessment of contractile function in relation to MYL1 expression or manipulation.
Organ-on-chip technologies that integrate multiple tissue types could illuminate MYL1's role in interactions between muscle and other tissues, such as neurons, blood vessels, or immune cells . These systems provide controlled environments for studying complex physiological processes while maintaining experimental tractability. The ability to incorporate patient-derived cells into these models further enhances their translational relevance, potentially enabling personalized testing of MYL1-targeted interventions.
Looking further ahead, advances in 3D bioprinting may eventually enable the creation of complex muscle constructs with precisely controlled spatial organization of different cell types and extracellular matrix components. Such systems would offer unprecedented opportunities for studying MYL1's role in muscle architecture and function. These engineered tissues could also serve as platforms for high-throughput screening of compounds that modulate MYL1 expression or function, accelerating the development of potential therapeutics for MYL1-associated diseases .
Integrating expertise across multiple disciplines holds tremendous potential for accelerating progress in MYL1 research. Collaborations between molecular biologists, biomedical engineers, and clinicians could bridge the gap between fundamental mechanistic insights and practical clinical applications. Engineers can develop sophisticated systems for monitoring muscle function in relation to MYL1 expression, while clinicians provide crucial insights into disease phenotypes and patient needs .
Computational biology and artificial intelligence approaches offer powerful tools for analyzing complex datasets and generating testable hypotheses about MYL1 function. Machine learning algorithms applied to multi-omics data could identify previously unrecognized patterns in MYL1 expression or regulation across diverse physiological and pathological contexts . These computational predictions can then guide focused experimental investigations, creating a productive cycle of hypothesis generation and validation.
Public-private partnerships bringing together academic researchers, biotechnology companies, and funding agencies could accelerate the translation of MYL1 research findings into clinical applications. Such collaborations might focus on developing standardized assays for measuring MYL1 expression in clinical samples, creating research tools for manipulating MYL1 in experimental systems, or conducting preclinical testing of potential MYL1-targeted therapeutics . By combining diverse expertise and resources, these interdisciplinary initiatives could overcome traditional barriers to progress and significantly accelerate the impact of MYL1 research on human health.
Myosin Light Chain 1 (MLC1) is a crucial component of the myosin motor protein complex, which plays a vital role in muscle contraction and various cellular processes. Myosin itself is a large hexameric protein composed of two heavy chains and two pairs of light chains: the essential or alkali myosin light chain 1 (MLC1) and the regulatory myosin light chain 2 (MLC2) .
MLC1 is a small polypeptide subunit of myosin, belonging to the EF-hand family of Ca²⁺-binding proteins . It contains two Ca²⁺-binding EF-hand motifs, which are essential for its function. The primary role of MLC1 is to stabilize the α-helical neck region of the myosin heavy chain (MHC) by binding in tandem where the myosin head attaches to the myosin tail . This stabilization is crucial for the proper assembly and function of the myosin motor protein.
The MYL1 gene encodes the myosin alkali light chain expressed in fast skeletal muscle . In humans, the MYL1 gene is localized to chromosome 2q32.1-qter . The gene produces two transcript variants, resulting in two alkali myosin light chains: MLC1f and MLC3f, which are differentially regulated throughout development .
MLC1, along with MLC2, contributes to the regulation of muscle contraction. Myosin light chain kinase (MLCK) is a Ca²⁺/calmodulin-dependent kinase that phosphorylates MLC2 to stimulate the interaction of myosin with actin thin filaments, leading to muscle contraction . Although MLC1 does not undergo phosphorylation like MLC2, it plays a structural role in stabilizing the myosin complex and ensuring efficient force transduction during muscle contraction .
Recombinant MLC1 is produced using recombinant DNA technology, which involves inserting the MYL1 gene into an expression system, such as bacteria or yeast, to produce the protein in large quantities. This recombinant protein is used in various research applications to study muscle physiology, myosin function, and related diseases.
Mutations in the MYL1 gene have been associated with several muscle-related diseases, including congenital myopathy 14 and actin-accumulation myopathy . These conditions are characterized by muscle weakness and structural abnormalities in muscle fibers. Research on recombinant MLC1 helps in understanding the molecular mechanisms underlying these diseases and developing potential therapeutic strategies.