MYL12A/MYL12B/MYL9 Antibody

What are MYL12A, MYL12B, and MYL9, and how do they differ functionally?

MYL12A, MYL12B, and MYL9 are myosin regulatory light chains (MRLCs/RLCs) that constitute crucial elements within Myosin II, exerting significant influence on diverse biological processes such as muscle contraction and cell division. These proteins share high sequence homology, with >96% amino acid similarity, making them difficult to differentiate with antibodies .

Functionally:

• MYL12A (also known as MLCB, MRLC3, RLC) and MYL12B (MRLC2, MYLC2B, MLC-2A, MLC-2) form complexes with actin heavy chains and are vital for regulating cell movement in non-muscle cells .

• MYL9 is primarily expressed in smooth muscle cells, though it's also found in non-muscle cells .

• All three act as regulatory components that control myosin activity by phosphorylating the head region of myosin heavy chains .

• Recent studies have identified these proteins as novel ligands for CD69, playing a crucial role in recruiting activated CD69+ T cells to inflamed tissues .

How is the expression of MYL12A/MYL12B/MYL9 distributed across different tissues?

The MRLC family is expressed in various cell types in a cell-specific manner:

• MYL12A/B and MYL9 are expressed in non-muscle cells .

• MYL9 is primarily located in the cytoplasm of smooth muscle and non-muscle cells .

• In the auditory system, droplet digital PCR revealed that hair cells (HCs) expressed MYL12A/B and MYL9, with only MYL12 expressed in the apical portion of HCs, whereas both MYL12 and MYL9 were expressed on inner sulcus cells (ISCs) .

• MYL9 is also found in striated skeletal muscle, though its precise function there is still being elucidated .

• Tissue analysis using the Broad Institute's GTEx Portal suggests that bladder and intestine express only low levels of MYL12B and little MYL12A .

• In inflammatory conditions, MYL9/12 proteins are found primarily on the vascular surface .

How can I select the appropriate MYL12A/MYL12B/MYL9 antibody for my research?

Selecting the appropriate antibody depends on your specific experimental goals:

• Consider target specificity:

  • Some antibodies like MYL9/MYL12A/B Antibody (D-9) detect all three proteins (MYL9, MYL12A, MYL12B) .

  • Others may be more specific, such as MYL12A Antibody (16287-1-AP) which predominantly targets MYL12A .

  • For phosphorylation studies, consider antibodies like Anti-MYL9 (pS20) + MYL12A (pS19) + MYL12B (pS20) antibody .

• Consider applications:

  • For western blotting: MYL12A/B Antibody (A-10) (sc-376606) or MYL12A antibody (16287-1-AP) .

  • For immunohistochemistry: MYL9/MYL12A/B Antibody (E-4) .

  • For immunofluorescence: MYL12A/MYL12B/MYL9 Antibody (PACO03361) .

• Consider species reactivity:

  • Most antibodies react with human, mouse, and rat samples .

  • Verify cross-reactivity in your specific model organism before beginning experiments.

How can I verify the specificity of my MYL12A/MYL12B/MYL9 antibody?

Verifying antibody specificity is crucial due to the high homology between these proteins:

• Knockout/knockdown validation:

  • Use cells with knockdown of MYL12A/12B as negative controls, as shown in studies where knockdown of MYL12A/12B in NIH 3T3 cells resulted in reduced detection .

• Phosphorylation state controls:

  • For phospho-specific antibodies, use dot blot analysis with phosphorylated and non-phosphorylated peptides as demonstrated with Anti-MYL9 (pS20) + MYL12A (pS19) + MYL12B (pS20) antibody .

• Tissue expression pattern validation:

  • Compare immunostaining patterns with known expression profiles: MYL9 is highly expressed in smooth muscle of the bladder but not in skeletal muscle .

• Multiple antibody comparison:

  • Use different antibodies targeting the same proteins and compare detection patterns to confirm specificity.

What are the optimal conditions for using MYL12A/MYL12B/MYL9 antibodies in Western blotting?

For optimal Western blotting results:

• Sample preparation:

  • For cell lysates: NIH/3T3 cells, Jurkat cells, HEK-293 cells, and HeLa cells have been successfully used .

  • For tissue lysates: Human skeletal muscle, mouse bladder, and mouse heart tissues work well .

• Dilution recommendations:

  • MYL12A antibody (16287-1-AP): 1:500-1:1000

  • MYL9/MYL12A/B Antibody (D-9): Typically 1:200-1:1000, specific dilution not provided in sources

  • MYL12A/B Antibody (A-10): Specific dilution not provided, comes as 200 μg/ml

• Expected molecular weight:

  • MYL12A: 19-20 kDa observed molecular weight (calculated: 20 kDa)

  • Similar molecular weights expected for MYL12B and MYL9 due to high sequence homology

• Detection systems:

  • Secondary antibodies: m-IgG Fc BP-HRP or m-IgGκ BP-HRP for mouse primary antibodies

  • For rabbit primaries like MYL12A antibody (16287-1-AP), use anti-rabbit HRP conjugates

How can I effectively use MYL12A/MYL12B/MYL9 antibodies for immunohistochemistry and immunofluorescence?

For effective immunohistochemistry (IHC) and immunofluorescence (IF):

• Tissue preparation:

  • Formalin-fixed, paraffin-embedded tissues work well

  • For MYL12A antibody (16287-1-AP), suggested antigen retrieval with TE buffer pH 9.0 or alternatively with citrate buffer pH 6.0

• Recommended dilutions:

  • MYL12A antibody (16287-1-AP): 1:20-1:200 for IHC

  • MYL12A/MYL12B/MYL9 Antibody (PACO03361): 1:100-1:300 for IHC and 1:200-1:1000 for IF

• Detection methods:

  • For IF, antibodies conjugated with fluorophores like FITC or Alexa Fluor® can be used

  • For dual staining, anti-Myl9/12 antibody can be combined with other markers like anti-α-SMA antibody to differentiate cell types

• Controls:

  • Use isotype controls to normalize fluorescence intensity measurements

  • For tissues like bladder where MYL9 is highly expressed, MYL9 knockout tissues can serve as negative controls

How are MYL12A/MYL12B/MYL9 implicated in inflammatory diseases, and how can antibodies be used to study these mechanisms?

MYL12A/MYL12B/MYL9 play significant roles in inflammatory conditions:

• Inflammatory bowel disease (IBD):

  • Strong expression of Myl9/12 is found in the inflamed gut of IBD patients and mice with DSS-induced colitis .

  • Administration of anti-Myl9/12 antibody to mice with DSS-induced colitis ameliorates inflammation and prolongs survival .

  • Plasma Myl9 levels in patients with active ulcerative colitis and Crohn's disease are significantly higher than in patients in remission, potentially serving as a biomarker for disease severity .

• Allergic airway inflammation:

  • MYL9/12 proteins form "Myl9 nets" at inflammatory sites, serving as a platform for the recruitment and maintenance of CD69-expressing inflammatory cells .

  • Blocking CD69-MYL9/12 interaction reduces allergic airway inflammation in mouse asthma models .

• Kawasaki disease:

  • Myl9 expression is significantly increased during Kawasaki disease vasculitis .

  • Myl9 levels may serve as a useful biomarker to estimate inflammation in this condition .

Research applications:

• Use anti-Myl9/12 antibodies for immunohistochemical analysis of inflamed tissues .

• Measure plasma Myl9 levels by ELISA to assess disease severity .

• Study the localization of CD69-expressing cells relative to Myl9/12-positive vessels in inflamed tissues .

What role do MYL12A/MYL12B/MYL9 play in cancer research, and how can antibodies targeting these proteins advance oncology studies?

MYL12A/MYL12B/MYL9 have emerging roles in cancer research:

• Cancer cell proliferation and migration:

  • Upregulation of MYL9 has been observed in several cancers, including colorectal cancer and glioblastoma, where it is thought to promote proliferation and migration of cancer cells .

  • MYL9 interacts with the transcriptional regulator YAP1 in colon carcinoma cells and alters the expression of YAP1-regulated genes .

• Metastasis mechanisms:

  • The myosin family, particularly myosin-regulated light chain RLCs (MYL12A and MYL12B), influences pathways related to cell proliferation and metastasis .

  • Phosphorylation status of these proteins affects cell migration capacity, which is crucial for metastatic spread.

Research applications:

• Use antibodies to study expression levels of MYL12A/MYL12B/MYL9 in tumor tissues compared to normal tissues.

• Employ phospho-specific antibodies to assess activation states in cancer cells.

• Investigate the effects of MLCK and ROCK pathway inhibitors on cancer cell migration using these antibodies as markers for pathway activity.

How does the phosphorylation state of MYL12A/MYL12B/MYL9 affect their function, and what methods can be used to study this?

Phosphorylation of MYL12A/MYL12B/MYL9 is crucial for their function:

• Regulatory mechanisms:

  • Phosphorylation is regulated by two main kinase systems: myosin light chain kinase (MLCK) and Rho-kinase (ROCK) .

  • In the presence of calcium and calmodulin, MLCK phosphorylates these light chains, enhancing actin-activated myosin ATPase activity .

  • Phosphorylation directly influences the contractile force generated during muscle contraction and affects cell migration in non-muscle cells .

• Specific phosphorylation sites:

  • Key phosphorylation sites include S20 in MYL9, S19 in MYL12A, and S20 in MYL12B .

  • Phosphorylation at these sites can be detected using phospho-specific antibodies like Anti-MYL9 (pS20) + MYL12A (pS19) + MYL12B (pS20) antibody .

Research methods:

• Use phospho-specific antibodies for western blotting, immunofluorescence, or ELISA to detect phosphorylation states .

• Combine with MLCK inhibitors like ML-7 to study the effects of reduced phosphorylation .

• Use in vitro phosphorylation assays with purified proteins and kinases to study direct phosphorylation events .

• Employ quantitative methods like dot blot analysis to differentiate between different phosphorylation states (e.g., single vs. dual phosphorylation) .

How can I study the interaction between MYL12A/MYL12B/MYL9 and their binding partners in complex biological systems?

To study interactions between MYL12A/MYL12B/MYL9 and their binding partners:

• Co-immunoprecipitation approaches:

  • Use antibodies like MYL9/MYL12A/B Antibody (E-4) AC (agarose conjugated) for immunoprecipitation .

  • Previous studies have shown that immunoprecipitation with antibodies that recognize MYL9, MYL12A, and MYL12B pulls down different myosin II MHCs in different tissues .

  • In bladder tissue, MYL9/12A/12B interacts with MYH11, whereas in skeletal muscle, they interact with MYH1 and MYH2 .

• Proteomic analysis:

  • Comprehensive interaction analysis has shown that MYL12A, MYL12B, and MYL9 can interact with various MHC IIs in diverse cell and tissue types, but do so optimally with non-muscle types of MHC II .

  • Proteomic analysis demonstrated that all three are associated with the MHCs MYH9 (NMHC IIA) and MYH10 (NMHC IIB), as well as the essential light chain MYL6, in NIH 3T3 fibroblasts .

• Functional interaction studies:

  • Study the CD69-MYL9/12 interaction by analyzing the recruitment of CD69-expressing cells to Myl9/12-positive vessels in inflamed tissues .

  • Investigate the effects of blocking this interaction using anti-Myl9/12 antibodies in disease models .

• In vitro binding assays:

  • Use purified MYL12B in combination with other proteins for in vitro phosphorylation and binding studies .

  • Expression systems can be optimized based on previous protocols for MYL2 genes .

What are the most reliable approaches for quantifying MYL12A/MYL12B/MYL9 in complex biological samples?

For reliable quantification of MYL12A/MYL12B/MYL9 in biological samples:

• ELISA techniques:

  • Commercial ELISA kits like the Human MLC2/MYL9 ELISA Kit (LifeSpan BioSciences) can be used to measure Myl9 levels in human plasma and culture supernatants .

  • Cusabio offers validated ELISA systems where immobilized Human MYL12A at 2μg/mL can bind Anti-MYL9 recombinant antibody with an EC50 of 5.325-6.456 ng/mL .

• Western blotting quantification:

  • Use antibodies validated for western blotting like MYL12A antibody (16287-1-AP) at dilutions of 1:500-1:1000 .

  • Include loading controls and standard curves with purified proteins for accurate quantification.

  • Expect to observe molecular weights of 19-20 kDa .

• Fluorescence-based quantification:

  • Measure fluorescence intensity of immunostained tissues, normalizing to isotype controls as demonstrated in Kawasaki disease studies .

  • This approach can be used to compare expression levels between different experimental conditions or disease states.

• Droplet digital PCR:

  • For mRNA quantification, use specific probes for MYL12A (e.g., Bio-Rad dRnoCPE5148326), MYL12B (dRnoCPE5151868), and MYL9 (dRnoCPE5149924) .

  • This method provides absolute quantification of transcript levels with high sensitivity.