NHLH1 Human
Description
Gene Structure and Protein Domains
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Protein Domains:
| Feature | Description |
|---|---|
| Protein Length | 133 amino acids |
| Aliases | HEN1, NSCL, NSCL1, bHLHa35 |
| Interactome | Partners include NEUROD1, LMO2, and BHLHE22 |
Neuronal Differentiation
NHLH1 regulates neurogenesis and neuronal identity:
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Midbrain Dopaminergic Neurons (mDANs):
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Cerebellar Granule Cells:
Metabolic Regulation
Cancer
Neurological Disorders
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Parkinson’s Disease: mDAN degeneration linked to NHLH1 dysregulation .
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Cleft Palate: Isolated cases associated with NHLH1 variants .
Upstream Regulators
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Shh/Gli Pathway: Directly activates NHLH1 transcription via Gli1 binding to its promoter .
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LBX1 and NR2F1/2: Co-regulate mDAN differentiation with NHLH1 .
Downstream Targets
Protein Interaction Network
| Partner | Role | Interaction Score |
|---|---|---|
| NEUROD1 | Neurogenic differentiation | 0.666 |
| LMO2 | Erythroid development | 0.637 |
| BHLHE22 | Represses neuronal differentiation | 0.533 |
mDAN Differentiation
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KD Effects:
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Overexpression:
Therapeutic Targets
Product Specs
Q&A
Basic Research Questions
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What is NHLH1 and what is its basic function in human neural development?
NHLH1 (also known as NSCL1) is a transcription factor belonging to the basic helix-loop-helix (bHLH) family of proteins. It plays critical roles during neural development, particularly in cerebellar formation. Gene expression profiling of developing mouse cerebella reveals NHLH1 as part of a gene cluster whose expression correlates with Hedgehog (HH) pathway activity, with peak expression around postnatal day 7 followed by reduced expression afterward . This developmental regulation suggests important temporal functions in neurogenesis. NHLH1 acts primarily as a transcriptional activator for downstream genes involved in neuronal migration and axon guidance, including Robo3 . For studying NHLH1 function, researchers have employed knockout models, cell culture systems, and reporter assays to demonstrate its transcriptional capabilities .
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Where is NHLH1 primarily expressed in the human body and how is it regulated?
NHLH1 shows tissue-specific expression primarily in neural tissues during development. In the developing mouse brain, NHLH1 expression follows a specific temporal pattern with highest expression between postnatal days 2-14, peaking around day 7, and then declining . The gene is directly regulated by the Sonic Hedgehog (Shh) pathway via the Gli1 transcription factor, which binds to a Gli-binding site approximately 700 bp upstream of the transcriptional start site .
Developmental Stage NHLH1 Relative Expression Shh Pathway Activity Early postnatal (P1-P2) Moderate Increasing Mid postnatal (P7) High (peak) High Late postnatal (P14) Declining Declining Adult Low Low Methodologically, researchers can analyze NHLH1 expression using quantitative PCR, in situ hybridization, or immunohistochemistry with appropriate temporal controls to account for its dynamic expression pattern. For mechanistic studies of regulation, electrophoretic mobility shift assays (EMSA) and luciferase reporter assays have successfully demonstrated direct regulation by Gli1 .
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What is the molecular structure of NHLH1 and how does it function as a transcription factor?
NHLH1 contains a characteristic helix-loop-helix (HLH) domain that is essential for its function . This structural element mediates protein-protein interactions, allowing NHLH1 to form homodimers or heterodimers with various partners. The complete coding sequence of mouse NHLH1 (GenBank accession: NM_010916) has been cloned and studied in experimental contexts .
Functionally, NHLH1 operates through:
Functional Domain Role in Transcriptional Regulation Basic domain DNA binding to E-box sequences HLH domain Protein-protein interactions with partners Transactivation domain Recruitment of transcriptional machinery NHLH1 can interact with multiple cofactors, including class I bHLH proteins (E12, E47), LIM-only proteins (Lmo1-4), and signal transducer and activator of transcription 3 (STAT3) . These interactions modulate its transcriptional activity and target specificity. Experimental approaches using VP16- and EnR-fusions have demonstrated that NHLH1 functions as a transcriptional activator for targets like Robo3 .
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What methodological approaches are most effective for studying NHLH1 expression patterns?
Researchers employ multiple complementary techniques to study NHLH1 expression:
Technique Application for NHLH1 Research Advantages Quantitative PCR (qPCR) Measuring mRNA levels in tissue samples Precise quantification, useful for developmental time courses In situ hybridization Spatial localization in tissue sections Cellular resolution within intact tissues Immunohistochemistry Protein localization in tissues Detection of post-translational modifications Western blotting Protein expression levels Quantification of protein levels across conditions Reporter gene assays Promoter activity analysis Direct measurement of transcriptional regulation For temporal studies, it's critical to collect samples at multiple developmental timepoints (P1-P14 in mice) to capture the dynamic expression pattern . For human samples, comparison between fetal, postnatal, and adult cerebella provides insight into developmental regulation . When analyzing NHLH1 in pathological contexts like medulloblastoma, researchers should include appropriate normal tissue controls and stratify samples based on molecular subtypes .
Product Science Overview
NHLH1 was first identified by Begley et al. in 1992 . The gene was discovered based on its hybridization to SCL (TAL1), a gene involved in T-cell acute lymphoblastic leukemia. The novel gene was initially referred to as NSCL (Nervous System-specific Helix-Loop-Helix) due to its expression in the developing nervous system . The murine homolog of NHLH1, known as Nscl, was also identified around the same time .
The NHLH1 gene is located on chromosome 1q23.2 in humans . It encodes a protein of approximately 14.8 kDa, consisting of 133 amino acids . The protein shares significant sequence identity with other members of the HLH family, particularly in the HLH domain, which is essential for its function as a transcription factor .
NHLH1 is expressed predominantly in the developing nervous system, where it is believed to play a role in the differentiation and development of neural cells . The gene is coexpressed with a highly related protein, NHLH2, in human neuroblastoma cell lines .
NHLH1 functions as a DNA-binding protein and is involved in the regulation of gene expression by forming dimers with other HLH proteins . It has been shown to interact with LMO2 and LMO4, two other proteins involved in transcriptional regulation . LMO4, in particular, can modulate the transcriptional activity of NHLH1 and influence neurite extension in rat hippocampal precursor cells .
The NHLH1 gene has been mapped to chromosome 1q23.2 in humans . In mice, the gene is located on chromosome 1 and is closely linked to the serum amyloid P locus . NHLH1 null mice, which lack the functional gene, have been developed as a model to study its role in development. These mice exhibit a predisposition to premature, adult-onset, unexpected death, highlighting the gene’s importance in normal physiological processes .
Mutations or dysregulation of NHLH1 have been implicated in various developmental disorders and diseases. The gene’s involvement in the development of the nervous system suggests that it may play a role in neurodevelopmental disorders . Additionally, its interaction with other transcription factors involved in tumorigenesis indicates a potential role in cancer biology .
