CIITA

Class II, major histocompatibility complex, transactivator
Identifiers
Symbols	CIITA ; C2TA; CIITAIV; MHC2TA; NLRA
External IDs	OMIM: 600005 MGI: 108445 HomoloGene: 207 GeneCards: CIITA Gene
EC number	2.7.11.1
Gene ontology Molecular function • DNA binding • transcription coactivator activity • protein binding • ATP binding • GTP binding • protein C-terminus binding • kinase activity • transferase activity, transferring acyl groups • protein complex binding • activating transcription factor binding • transcription regulatory region DNA binding Cellular component • nucleoplasm • PML body Biological process • negative regulation of transcription from RNA polymerase II promoter • transcription, DNA-templated • immune response • phosphorylation • cytokine-mediated signaling pathway • negative regulation of collagen biosynthetic process • response to interferon-gamma • positive regulation of MHC class I biosynthetic process • positive regulation of MHC class II biosynthetic process • negative regulation of transcription, DNA-templated • positive regulation of transcription, DNA-templated • positive regulation of transcription from RNA polymerase II promoter • response to antibiotic • interferon-gamma-mediated signaling pathway Sources: Amigo / QuickGO
RNA expression pattern
File:PBB GE CIITA 211884 s at tn.png
File:PBB GE CIITA 210925 at tn.png
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	4261	12265
Ensembl	ENSG00000179583	ENSMUSG00000022504
UniProt	P33076	P79621
RefSeq (mRNA)	NM_000246	NM_001243760
RefSeq (protein)	NP_000237	NP_001230689
Location (UCSC)	Chr 16: 10.88 – 10.93 Mb	Chr 16: 10.49 – 10.53 Mb
PubMed search	[1]	[2]

CIITA is a human gene which encodes a protein called the class II, major histocompatibility complex, transactivator. Mutations in this gene are responsible for the bare lymphocyte syndrome in which the immune system is severely compromised and cannot effectively fight infection. Chromosomal rearrangement of CIITA is involved in the pathogenesis of Hodgkin lymphoma and primary mediastinal B cell lymphoma.

Function

CIITA mRNA can only be detected in human leukocyte antigen (HLA) system class II-positive cell lines and tissues. This highly restricted tissue distribution suggests that expression of HLA class II genes is to a large extent under the control of CIITA. However CIITA does not appear to directly bind to DNA. Instead CIITA functions through activation of the transcription factor RFX5. Hence CIITA is classified as a transcriptional coactivator.

The CIITA protein contains an acidic transcriptional activation domain, 4 LRRs (leucine-rich repeats) and a GTP binding domain. The protein uses GTP binding to facilitate its own transport into the nucleus. Once in the nucleus, the protein acts as a positive regulator of class II major histocompatibility complex gene transcription, and is often referred to as the "master control factor" for the expression of these genes.

Interactions

CIITA has been shown to interact with:

• MAPK1,
• Nuclear receptor coactivator 1,
• RFX5,
• RFXANK,
• XPO1, and
• ZXDC.

See also

• MHC class II

External links

• MHC class II transactivator protein at the US National Library of Medicine Medical Subject Headings (MeSH)

This article incorporates text from the United States National Library of Medicine, which is in the public domain.