MYLK: Myosin Light Chain Kinase Gene
Key regulator of smooth muscle contraction and vascular integrity
Gene Information Card
| Symbol | MYLK |
|---|---|
| Full Name | Myosin Light Chain Kinase |
| Gene Type | Protein coding |
| Chromosomal Location | 3q21.1 |
| NCBI Gene ID | 4638 ncbi.nlm.nih.gov/gene/4638 |
| Ensembl ID | ENSG00000065534 |
| UniProt ID | Q15746 |
| OMIM ID | 600922 |
| HGNC ID | 7590 |
| Aliases | MLCK, MLCK1, smMLCK, MLCK108, MLCK210, MLCK-210, MLCK-108 |
Description
The MYLK gene encodes myosin light chain kinase (MLCK), a calcium/calmodulin-dependent enzyme that phosphorylates myosin regulatory light chains to initiate smooth muscle contraction. MLCK also regulates cytoskeletal dynamics, cell migration, and vascular permeability. Alternative splicing produces multiple isoforms, including smooth muscle (smMLCK) and non-muscle (nmMLCK) variants.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Aortic aneurysm, familial thoracic 7 | Loss-of-function mutations in MYLK impair smooth muscle contraction, leading to aortic wall weakness and aneurysm formation. | OMIM #613780; ClinVar |
| Asthma | MYLK variants are associated with altered airway smooth muscle contractility and hyperresponsiveness. | NCBI Gene; PubMed |
| Colorectal cancer | MYLK overexpression promotes tumor cell migration and invasion via cytoskeletal remodeling. | COSMIC; PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Smooth muscle (aorta, intestine, bladder) | High (nTPM > 50) | High |
| Heart | Moderate (nTPM 10-50) | Moderate |
| Lung | Moderate (nTPM 10-50) | Moderate |
| Brain | Low (nTPM < 10) | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Aortic smooth muscle cells | High | Primary cell line |
| HEK 293 | Moderate | Embryonic kidney |
| HeLa | Low | Cervical cancer |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.5275C>T (p.Arg1759Ter) | Nonsense | Rare | Loss of function; associated with thoracic aortic aneurysm |
| c.1441G>A (p.Gly481Arg) | Missense | Rare | Reduced kinase activity; linked to asthma |
| c.5275C>T (p.Arg1759Ter) | Nonsense | Rare | Loss of function; associated with thoracic aortic aneurysm |
Mutation functional classification
Loss of Function (LOF)
Nonsense and frameshift mutations in MYLK lead to truncated or absent MLCK protein, impairing smooth muscle contraction and causing aortic aneurysm.
Gain of Function (GOF)
Not well documented; some missense variants may increase kinase activity but evidence is limited.
Dominant Negative (DN)
Some missense mutations may produce a dominant-negative effect by interfering with calmodulin binding or substrate phosphorylation.
View complete mutation data：
Gene Ontology (GO)
| • GO:0004687 - myosin light chain kinase activity | • GO:0005516 - calmodulin binding |
| • GO:0006936 - muscle contraction | • GO:0031032 - actomyosin structure organization |
| • GO:0007165 - signal transduction |
Pathways
• hsa04270: Vascular smooth muscle contraction
• hsa04810: Regulation of actin cytoskeleton
• hsa04530: Tight junction
Protein Summary
Myosin light chain kinase (MLCK) is a 210 kDa (smooth muscle isoform) or 108 kDa (non-muscle isoform) serine/threonine kinase that phosphorylates the regulatory light chain of myosin II (MLC2) at Ser19. This phosphorylation activates myosin ATPase and promotes actin-myosin cross-bridge cycling, essential for smooth muscle contraction. MLCK also localizes to cell-cell junctions and regulates endothelial barrier function. The protein contains an N-terminal actin-binding domain, a central catalytic domain, and a C-terminal calmodulin-binding domain.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MYLK Knockout Caco-2 Cell Line | EDJ-KQ11 | Human | 4638 | Details Get a Quote |
| MYLK3 Knockout HEK293 Cell Line | EDJ-KQ853 | Human | 91807 | Details Get a Quote |
| MYLK Knockout HEK293 Cell Line | EDJ-KQ1434 | Human | 4638 | Details Get a Quote |
| MYLK2 Knockout HEK293 Cell Line | EDJ-KQ1435 | Human | 85366 | Details Get a Quote |
| MYLK4 Knockout HEK293 Cell Line | EDJ-KQ1437 | Human | 340156 | Details Get a Quote |
| MYLK Knockout A-549 Cell Line | EDJ-KQ20978 | Human | 4638 | Details Get a Quote |
| MYLK Knockout HCT 116 Cell Line | EDJ-KQ20979 | Human | 4638 | Details Get a Quote |
| MYLK Knockout HeLa Cell Line | EDJ-KQ20980 | Human | 4638 | Details Get a Quote |
| MYLK2 Knockout HCT 116 Cell Line | EDJ-KQ20981 | Human | 85366 | Details Get a Quote |
| MYLK2 Knockout HeLa Cell Line | EDJ-KQ20982 | Human | 85366 | Details Get a Quote |
| MYLK3 Knockout HeLa Cell Line | EDJ-KQ20983 | Human | 91807 | Details Get a Quote |
| MYLK4 Knockout HeLa Cell Line | EDJ-KQ59668 | Human | 340156 | Details Get a Quote |
| MYLK2 Knockout A-549 Cell Line | EDJ-KQ66207 | Human | 85366 | Details Get a Quote |
| MYLK3 Knockout A-549 Cell Line | EDJ-KQ66309 | Human | 91807 | Details Get a Quote |
| MYLK4 Knockout A-549 Cell Line | EDJ-KQ68140 | Human | 340156 | Details Get a Quote |
Displaying Records 1 To 15 Of 18 Records
