TMEM256
Transmembrane protein 256
Also known as: C17orf61, MGC40107, TM256_HUMAN
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- Q8N2U0
- Gene
- TMEM256
- Ensembl
- ENSG00000205544
- Chromosome
- 17
- Canonical length
- 113 aa
- Protein class
- Predicted intracellular proteins, Predicted membrane proteins
- Subcellular location
- Vesicles
OverviewNCBI Gene
Located in extracellular exosome and mitochondrion. [provided by Alliance of Genome Resources, Jul 2025]
Canonical amino-acid sequenceUniProt
113 residues, UniProt reviewed canonical sequence.
>Q8N2U0|TMEM256
1 MAGPAAAFRR LGALSGAAAL GFASYGAHGA QFPDAYGKEL FDKANKHHFL HSLALLGVPH
61 CRKPLWAGLL LASGTTLFCT SFYYQALSGD PSIQTLAPAG GTLLLLGWLA LALLocalizationUniProt · AlphaFold · HPA
Whether an antibody against TMEM256 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
- 2
- Mean surface accessibility (rSASA)
- 0.31
- Highest tissue expression
- 195 nTPM
Expression across tissuesHPA
Tissue
- liver: 195 nTPM
- kidney: 169 nTPM
- spinal cord: 136 nTPM
- pancreas: 128 nTPM
- midbrain: 112 nTPM
- heart muscle: 109 nTPM
Single-cell type
- enterocytes: 660 nCPM
- parietal cells: 401 nCPM
- hepatocytes: 356 nCPM
- gastric chief cells: 298 nCPM
- oocytes: 258 nCPM
- epididymal efferent duct absorptive cells: 257 nCPM
Immune cell
- plasmacytoid DC: 83 nTPM
- total PBMC: 78 nTPM
- memory B-cell: 78 nTPM
- naive B-cell: 69 nTPM
- classical monocyte: 63 nTPM
- myeloid DC: 60 nTPM
Brain region
- white matter: 41 nTPM
- spinal cord: 32 nTPM
- cerebellum: 32 nTPM
- medulla oblongata: 32 nTPM
- basal ganglia: 29 nTPM
- hypothalamus: 28 nTPM
DiseaseUniProt · ClinVar · IEDB · PubMed
Four sources answering four different questions about TMEM256.
Disease | GeneticClinVar
1 pathogenic / likely-pathogenic of 23 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)
- 1.71
- gnomAD pLI
- 0
- gnomAD missense Z
- 0.18
- DepMap mean gene effect
- -0.01
- DepMap dependency class
- none
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
Cellular components
Protein domainsUniProt · Pfam · InterPro
- Protein of unknown function DUF423
- Protein of unknown function (DUF423)
KeywordsUniProt
Antibody and autoantibody relevanceSeroatlas analysis
Seroatlas reads TMEM256 as an antibody target. Whether an autoantibody or antibody against TMEM256 could matter depends on whether native TMEM256 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
TMEM256 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 TMEM256 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
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