Class II gene

From Wikipedia, the free encyclopedia

A class II gene is a type of gene that codes for a protein. Class II genes are transcribed by RNAP II[citation needed].

Class II genes have a promoter that may contain a TATA box.

Basal transcription of class II genes requires the formation of a preinitiation complex.

They are transcribed by RNA polymerase II, include both intron and exon, and code for polypeptide.

Major histocompatibility complex (MHC) class II genes are important in the immune response.[1]

Major histocompatibility complex (MHC) II is found on antigen-presenting cells (APCs) and functions to present exogenous proteins to CD4+ T cells.[2] MHC II thus plays an important role in activating the immune system in response to extracellular pathogens via activation of CD4+ T cells.[2] MHC class II molecules are differentially expressed across multiple cell-types.[3] For example, MHC II molecules are constitutively expressed in thymic epithelial cells and antigen-presenting cells (APC's), whereas they undergo interferon-γ-mediated expression in other cell types.[3] Central to the regulation of the complex gene-expression profile exhibited by MHC class II molecules is a single master regulatory factor known as the class II transactivator (CIITA).[3] CIITA is a non-DNA-binding co-activator whose expression is tightly controlled by a regulatory region containing three independent promoters (pI, pIII and pIV).[3]


  1. ^ Handunnetthi, L; Ramagopalan, SV; Ebers, GC; Knight, JC (2010). "Regulation of major histocompatibility complex class II gene expression, genetic variation and disease". Genes Immun. 11 (2): 99–112. doi:10.1038/gene.2009.83. PMC 2987717. PMID 19890353.
  2. ^ a b Suzuki, K.; Luo, Y. (2017). "Histone Acetylation and the Regulation of Major Histocompatibility Class II Gene Expression". Advances in Protein Chemistry and Structural Biology. 106: 71–111. doi:10.1016/bs.apcsb.2016.08.002. ISBN 9780128123928. ISSN 1876-1623. PMID 28057216.
  3. ^ a b c d Reith, Walter; LeibundGut-Landmann, Salomé; Waldburger, Jean-Marc (October 2005). "Regulation of MHC class II gene expression by the class II transactivator". Nature Reviews. Immunology. 5 (10): 793–806. doi:10.1038/nri1708. ISSN 1474-1733. PMID 16200082. S2CID 10511989.