Seroatlas · Human Serome Atlas

MYL9

Myosin regulatory light polypeptide 9

Also known as: LC20, MLC2, MRLC1, MYL9_HUMAN, MYRL2

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
P24844
Gene
MYL9
Ensembl
ENSG00000101335
Chromosome
20
Canonical length
172 aa
Protein class
Disease related genes, Human disease related genes, Predicted intracellular proteins

OverviewNCBI Gene

Myosin, a structural component of muscle, consists of two heavy chains and four light chains. The protein encoded by this gene is a myosin light chain that may regulate muscle contraction by modulating the ATPase activity of myosin heads. The encoded protein binds calcium and is activated by myosin light chain kinase. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

172 residues, UniProt reviewed canonical sequence.

>P24844|MYL9
     1  MSSKRAKAKT TKKRPQRATS NVFAMFDQSQ IQEFKEAFNM IDQNRDGFID KEDLHDMLAS
    61  LGKNPTDEYL EGMMSEAPGP INFTMFLTMF GEKLNGTDPE DVIRNAFACF DEEASGFIHE
   121  DHLRELLTTM GDRFTDEEVD EMYREAPIDK KGNFNYVEFT RILKHGAKDK DD

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against MYL9 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Intracellular
Secreted
No
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.41
Highest tissue expression
7,663 nTPM

Expression across tissuesHPA

Tissue

  • blood vessel: 7,663 nTPM
  • colon: 7,657 nTPM
  • urinary bladder: 4,290 nTPM
  • endometrium: 2,468 nTPM
  • prostate: 2,236 nTPM
  • heart muscle: 2,176 nTPM

Single-cell type

  • smooth muscle cells: 6,680 nCPM
  • vascular smooth muscle cells: 4,663 nCPM
  • decidual stromal cells: 3,124 nCPM
  • breast myoepithelial cells: 2,812 nCPM
  • platelets: 2,068 nCPM
  • hepatic stellate cells: 2,014 nCPM

Immune cell

  • total PBMC: 7.2 nTPM
  • eosinophil: 2.2 nTPM
  • neutrophil: 1.9 nTPM
  • memory B-cell: 0.9 nTPM
  • plasmacytoid DC: 0.4 nTPM
  • myeloid DC: 0.3 nTPM

Brain region

  • choroid plexus: 110 nTPM
  • cerebral cortex: 52 nTPM
  • basal ganglia: 48 nTPM
  • medulla oblongata: 28 nTPM
  • pons: 28 nTPM
  • thalamus: 28 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about MYL9.

Disease | AllUniProt

Conditions MYL9 is implicated in, by any mechanism.

  • Megacystis-microcolon-intestinal hypoperistalsis syndrome 4 (MMIHS4) MIM:619365

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
1.49
gnomAD pLI
0.02
gnomAD missense Z
1.17
DepMap mean gene effect
-0.11
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 4% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of MYL9 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads MYL9 as an antibody target. Whether an autoantibody or antibody against MYL9 could matter depends on whether native MYL9 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

MYL9 is annotated as predominantly intracellular. Intracellular proteins are common autoantibody markers, becoming visible to the immune system after cell injury or altered processing, but are usually markers of disease rather than direct drivers.

Annotation status

The present source text does not explicitly label MYL9 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/MYL9. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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