Seroatlas · Human Serome Atlas

MYO18B

Unconventional myosin-XVIIIb

Also known as: BK125H2.1, MY18B_HUMAN

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

Protein identityUniProt · HPA

UniProt accession
Q8IUG5
Gene
MYO18B
Ensembl
ENSG00000133454
Chromosome
22
Canonical length
2567 aa
Protein class
Disease related genes, Human disease related genes, Predicted intracellular proteins
Subcellular location
Nucleoplasm,Centrosome
Quaternary structure
Homodimer

OverviewNCBI Gene

The protein encoded by this gene may regulate muscle-specific genes when in the nucleus and may influence intracellular trafficking when in the cytoplasm. The encoded protein functions as a homodimer and may interact with F actin. Mutations in this gene are associated with lung cancer. [provided by RefSeq, Jul 2008]

Canonical amino-acid sequenceUniProt

2567 residues, UniProt reviewed canonical sequence.

>Q8IUG5|MYO18B
     1  MAISSRLALW EQKIREEDKS PPPSSPPPLF SVIPGGFIKQ LVRGTEKEAK EARQRKQLAV
    61  ASPEREIPEI SISQPNSKSS SGTRSGSQQI SQDDQSSSPG SSDILGKESE GSRSPDPEQM
   121  TSINGEKAQE LGSSATPTKK TVPFKRGVRR GDVLLMVAKL DPDSAKPEKT HPHDAPPCKT
   181  SPPATDTGKE KKGETSRTPC GSQASTEILA PKAEKTRTGG LGDPGQGTVA LKKGEEGQSI
   241  VGKGLGTPKT TELKEAEPQG KDRQGTRPQA QGPGEGVRPG KAEKEGAEPT NTVEKGNVSK
   301  DVGSEGKHVR PQIPGRKWGG FLGRRSKWDG PQNKKDKEGV LLSKAEKTGE PQTQMEKTSQ
   361  VQGELGDDLR MGEKAGELRS TTGKAGESWD KKEKMGQPQG KSGNAGEARS QTEKGCEAPK
   421  EVSTMVESPA APGKGGWPGS RGQEAEEPCS RAGDGAGALE TELEGPSQPA LEKDAERPRI
   481  RKENQDGPAP QEEGKGGQSR DSDQAPEDRW YEAEKVWLAQ KDGFTLATVL KPDEGTADLP
   541  AGRVRLWIDA DKTITEVDEE HVHRANPPEL DQVEDLASLI SVNESSVLNT LLQRYKAQLL
   601  HTCTGPDLIV LQPRGPSVPS AGKVPKGRRD GLPAHIGSMA QRAYWALLNQ RRDQSIVALG
   661  WSGAGKTTCC EQVLEHLVGM AGSVDGRVSV EKIRATFTVL RAFGSVSMAH SRSATRFSMV
   721  MSLDFNATGR ITAAQLQTML LEKSRVARQP EGESNFLVFS QMLAGLDLDL RTELNLHQMA
   781  DSSSFGMGVW SKPEDKQKAA AAFAQLQGAM EMLGISESEQ RAVWRVLAAI YHLGAAGACK
   841  VGRKQFMRFE WANYAAEALG CEYEELNTAT FKHHLRQIIQ QMTFGPSRWG LEDEETSSGL
   901  KMTGVDCVEG MASGLYQELF AAVVSLINRS FSSHHLSMAS IMVVDSPGFQ NPRHQGKDRA
   961  ATFEELCHNY AHERLQLLFY QRTFVSTLQR YQEEGVPVQF DLPDPSPGTT VAVVDQNPSQ
  1021  VRLPAGGGAQ DARGLFWVLD EEVHVEGSSD SVVLERLCAA FEKKGAGTEG SSALRTCEQP
  1081  LQCEIFHQLG WDPVRYDLTG WLHRAKPNLS ALDAPQVLHQ SKREELRSLF QARAKLPPVC
  1141  RAVAGLEGTS QQALQRSRMV RRTFASSLAA VRRKAPCSQI KLQMDALTSM IKRSRLHFIH
  1201  CLVPNPVVES RSGQESPPPP QPGRDKPGAG GPLALDIPAL RVQLAGFHIL EALRLHRTGY
  1261  ADHMGLTRFR RQFQVLDAPL LKKLMSTSEG IDERKAVEEL LETLDLEKKA VAVGHSQVFL
  1321  KAGVISRLEK QREKLVSQSI VLFQAACKGF LSRQEFKKLK IRRLAAQCIQ KNVAVFLAVK
  1381  DWPWWQLLGS LQPLLSATIG TEQLRAKEEE LTTLRRKLEK SEKLRNELRQ NTDLLESKIA
  1441  DLTSDLADER FKGDVACQVL ESERAERLQA FREVQELKSK HEQVQKKLGD VNKQLEEAQQ
  1501  KIQLNDLERN PTGGADEWQM RFDCAQMENE FLRKRLQQCE ERLDSELTAR KELEQKLGEL
  1561  QSAYDGAKKM AHQLKRKCHH LTCDLEDTCV LLENQQSRNH ELEKKQKKFD LQLAQALGES
  1621  VFEKGLREKV TQENTSVRWE LGQLQQQLKQ KEQEASQLKQ QVEMLQDHKR ELLGSPSLGE
  1681  NCVAGLKERL WKLESSALEQ QKIQSQQENT IKQLEQLRQR FELEIERMKQ MHQKDREDQE
  1741  EELEDVRQSC QKRLHQLEMQ LEQEYEEKQM VLHEKQDLEG LIGTLCDQIG HRDFDVEKRL
  1801  RRDLRRTHAL LSDVQLLLGT MEDGKTSVSK EELEKVHSQL EQSEAKCEEA LKTQKVLTAD
  1861  LESMHSELEN MTRNKSLVDE QLYRLQFEKA DLLKRIDEDQ DDLNELMQKH KDLIAQSAAD
  1921  IGQIQELQLQ LEEAKKEKHK LQEQLQVAQM RIEYLEQSTV DRAIVSRQEA VICDLENKTE
  1981  FQKVQIKRFE VLVIRLRDSL IKMGEELSQA ATSESQQRES SQYYQRRLEE LKADMEELVQ
  2041  REAEASRRCM ELEKYVEELA AVRQTLQTDL ETSIRRIADL QAALEEVASS DSDTESVQTA
  2101  VDCGSSGRKE MDNVSILSSQ PEGSLQSWLS CTLSLATDTM RTPSRQSATS SRILSPRINE
  2161  EAGDTERTQS ALALSRARST NVHSKTSGDK PVSPHFVRRQ KYCHFGDGEV LAVQRKSTER
  2221  LEPASSPLAS RSTNTSPLSR EKLPSPSAAL SEFVEGLRRK RAQRGQGSTL GLEDWPTLPI
  2281  YQTTGASTLR RGRAGSDEGN LSLRVGAKSP LEIEGAAGGL LRSTSLKCIS SDGVGGTTLL
  2341  PEKSKTQFSS CESLLESRPS MGRKLSSPTT PRDMLLSPTL RPRRRCLESS VDDAGCPDLG
  2401  KEPLVFQNRQ FAHLMEEPLG SDPFSWKLPS LDYERKTKVD FDDFLPAIRK PQTPTSLAGS
  2461  AKGGQDGSQR SSIHFETEEA NRSFLSGIKT ILKKSPEPKE DPAHLSDSSS SSGSIVSFKS
  2521  ADSIKSRPGI PRLAGDGGER TSPERREPGT GRKDDDVASI MKKYLQK

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against MYO18B 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)
0.45
Highest tissue expression
252 nTPM

Expression across tissuesHPA

Tissue

  • skeletal muscle: 252 nTPM
  • heart muscle: 114 nTPM
  • tongue: 52 nTPM
  • blood vessel: 14 nTPM
  • testis: 9.7 nTPM
  • salivary gland: 3 nTPM

Single-cell type

  • myonuclei: 1,232 nCPM
  • cardiomyocytes: 732 nCPM
  • myosatellite cells: 415 nCPM
  • thymic myoid cells: 333 nCPM
  • early spermatids: 141 nCPM
  • late primary spermatocytes: 65 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • thalamus: 5.3 nTPM
  • midbrain: 1.8 nTPM
  • medulla oblongata: 0.8 nTPM
  • amygdala: 0.7 nTPM
  • hypothalamus: 0.7 nTPM
  • pons: 0.7 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about MYO18B.

Disease | AllUniProt

Conditions MYO18B is implicated in, by any mechanism.

  • Klippel-Feil syndrome 4, autosomal recessive, with nemaline myopathy and facial dysmorphism (KFS4) MIM:616549

Disease | GeneticClinVar

142 pathogenic / likely-pathogenic of 2,517 ClinVar records.

Conditions with pathogenic or likely-pathogenic variants.

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)
0.72
gnomAD pLI
0
gnomAD missense Z
0.18
DepMap mean gene effect
0.03
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% 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

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads MYO18B as an antibody target. Whether an autoantibody or antibody against MYO18B could matter depends on whether native MYO18B is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

MYO18B 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 MYO18B as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/MYO18B. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...