CD99
CD99 antigen
Also known as: CD99_HUMAN, MIC2
Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene
Protein identityUniProt · HPA
- UniProt accession
- P14209
- Gene
- CD99
- Ensembl
- ENSG00000002586
- Chromosome
- X
- Canonical length
- 185 aa
- Protein class
- CD markers, Plasma proteins, Predicted intracellular proteins, Predicted membrane proteins
- Subcellular location
- Golgi apparatus
OverviewNCBI Gene
The protein encoded by this gene is a cell surface glycoprotein involved in leukocyte migration, T-cell adhesion, ganglioside GM1 and transmembrane protein transport, and T-cell death by a caspase-independent pathway. In addition, the encoded protein may have the ability to rearrange the actin cytoskeleton and may also act as an oncosuppressor in osteosarcoma. This gene is found in the pseudoautosomal region of chromosomes X and Y and escapes X-chromosome inactivation. There is a related pseudogene located immediately adjacent to this locus. [provided by RefSeq, Mar 2016]
Canonical amino-acid sequenceUniProt
185 residues, UniProt reviewed canonical sequence.
>P14209|CD99
1 MARGAALALL LFGLLGVLVA APDGGFDLSD ALPDNENKKP TAIPKKPSAG DDFDLGDAVV
61 DGENDDPRPP NPPKPMPNPN PNHPSSSGSF SDADLADGVS GGEGKGGSDG GGSHRKEGEE
121 ADAPGVIPGI VGAVVVAVAG AISSFIAYQK KKLCFKENAE QGEVDMESHR NANAEPAVQR
181 TLLEKLocalizationUniProt · AlphaFold · HPA
Whether an antibody against CD99 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
- Cell surface
- Secreted
- No
- Transmembrane segments
- 1
- Mean surface accessibility (rSASA)
- 0.66
- Highest tissue expression
- 523 nTPM
Expression across tissuesHPA
Tissue
- thymus: 523 nTPM
- blood vessel: 493 nTPM
- adipose tissue: 492 nTPM
- colon: 357 nTPM
- heart muscle: 352 nTPM
- cervix: 348 nTPM
Single-cell type
- platelets: 1,730 nCPM
- hofbauer cells: 1,448 nCPM
- pancreatic islet cells: 1,384 nCPM
- esophageal apical cells: 1,322 nCPM
- decidual stromal cells: 1,032 nCPM
- thymocytes: 874 nCPM
Immune cell
- total PBMC: 1,420 nTPM
- gdT-cell: 1,092 nTPM
- memory CD8 T-cell: 961 nTPM
- T-reg: 836 nTPM
- memory CD4 T-cell: 733 nTPM
- plasmacytoid DC: 683 nTPM
Brain region
- hypothalamus: 382 nTPM
- spinal cord: 331 nTPM
- white matter: 325 nTPM
- medulla oblongata: 306 nTPM
- midbrain: 234 nTPM
- pons: 219 nTPM
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)
- 0.97
- gnomAD pLI
- 0
- gnomAD missense Z
- -0.53
OntologyGO
Biological processes
Cellular components
Protein domainsUniProt · Pfam · InterPro
KeywordsUniProt
Antibody and autoantibody relevanceSeroatlas analysis
Seroatlas reads CD99 as an antibody target. Whether an autoantibody or antibody against CD99 could matter depends on whether native CD99 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.
CD99 is annotated at the cell surface, where native CD99 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.
Annotation status
The present source text does not explicitly label CD99 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.
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