CD4

CD4
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1CDH, 1CDI, 1CDJ, 1CDU, 1CDY, 1G9M, 1G9N, 1GC1, 1JL4, 1Q68, 1RZJ, 1RZK, 1WIO, 1WIP, 1WIQ, 2B4C, 2JKR, 2JKT, 2KLU, 2NXY, 2NXZ, 2NY0, 2NY1, 2NY2, 2NY3, 2NY4, 2NY5, 2NY6, 2QAD, 3B71, 3CD4, 3JWD, 3JWO, 3LQA, 3O2D, 3S5L, 3T0E, 4JM2, 1WBR, 3S4S, 4H8W, 4P9H, 4Q6I, 4R2G, 4R4H, 4RQS, 3J70, 5A7X, 5A8H, 5CAY
Identifiers
Aliases	CD4, CD4mut, CD4 molecule, OKT4D, IMD79
External IDs	OMIM: 186940 MGI: 88335 HomoloGene: 513 GeneCards: CD4
Gene location (Human) Chr. Chromosome 12 (human)[1] Band 12p13.31 Start 6,786,858 bp[1] End 6,820,799 bp[1]
Gene location (Mouse) Chr. Chromosome 6 (mouse)[2] Band 6 F2|6 59.17 cM Start 124,841,655 bp[2] End 124,865,184 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in monocyte lymph node spleen appendix gallbladder thymus upper lobe of left lung right lung right lobe of liver blood Top expressed in thymus lymph node blood spleen external carotid artery internal carotid artery superior frontal gyrus molar secondary oocyte globus pallidus More reference expression data BioGPS n/a
Gene ontology Molecular function transmembrane signaling receptor activity virus receptor activity protein homodimerization activity zinc ion binding extracellular matrix structural constituent enzyme binding immunoglobulin binding protein binding coreceptor activity interleukin-16 binding interleukin-16 receptor activity MHC class II protein binding identical protein binding protein tyrosine kinase binding signaling receptor activity protein kinase binding signaling receptor binding Cellular component endoplasmic reticulum lumen integral component of membrane early endosome membrane cell surface endoplasmic reticulum membrane membrane raft T cell receptor complex external side of plasma membrane plasma membrane clathrin-coated vesicle membrane integral component of plasma membrane Biological process transmembrane receptor protein tyrosine kinase signaling pathway defense response to Gram-negative bacterium positive regulation of protein kinase activity mitigation of host defenses by virus positive regulation of calcium-mediated signaling signal transduction helper T cell enhancement of adaptive immune response T cell selection response to estradiol induction by virus of host cell-cell fusion adaptive immune response response to vitamin D T cell differentiation cell surface receptor signaling pathway positive regulation of T cell proliferation positive regulation of peptidyl-tyrosine phosphorylation enzyme linked receptor protein signaling pathway T cell activation positive regulation of T cell activation maintenance of protein location in cell cytokine production T cell receptor signaling pathway immune system process positive regulation of calcium ion transport into cytosol regulation of T cell activation immune response cell adhesion viral process fusion of virus membrane with host plasma membrane membrane organization positive regulation of protein phosphorylation positive regulation of kinase activity interleukin-15-mediated signaling pathway positive regulation of I-kappaB kinase/NF-kappaB signaling positive regulation of MAPK cascade positive regulation of monocyte differentiation positive regulation of transcription, DNA-templated positive regulation of viral entry into host cell regulation of calcium ion transport positive regulation of ERK1 and ERK2 cascade cellular response to granulocyte macrophage colony-stimulating factor stimulus cytokine-mediated signaling pathway macrophage differentiation Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 920 12504 Ensembl ENSG00000010610 ENSMUSG00000023274 UniProt P01730 P06332 RefSeq (mRNA) NM_000616 NM_001195014 NM_001195015 NM_001195016 NM_001195017 NM_001382705 NM_001382706 NM_001382707 NM_001382714 NM_013488 RefSeq (protein) NP_000607 NP_001181943 NP_001181944 NP_001181945 NP_001181946 NP_001369634 NP_001369635 NP_001369636 NP_001369643 NP_038516 Location (UCSC) Chr 12: 6.79 – 6.82 Mb Chr 6: 124.84 – 124.87 Mb PubMed search [3] [4]
Wikidata
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CD4, Cluster of differentiation 4, extracellular
structure of T cell surface glycoprotein cd4, monoclinic crystal form
Identifiers
Symbol	CD4-extrcel
Pfam	PF09191
InterPro	IPR015274
SCOP2	1cid / SCOPe / SUPFAM
OPM superfamily	193
OPM protein	2klu
CDD	cd07695
Membranome	27
Available protein structures: Pfam   structures / ECOD   PDB RCSB PDB; PDBe; PDBj PDBsum structure summary

In molecular biology, CD4 (cluster of differentiation 4) is a glycoprotein that serves as a co-receptor for the T-cell receptor (TCR). CD4 is found on the surface of immune cells such as helper T cells, monocytes, macrophages, and dendritic cells. It was discovered in the late 1970s and was originally known as leu-3 and T4 (after the OKT4 monoclonal antibody that reacted with it) before being named CD4 in 1984.^[5] In humans, the CD4 protein is encoded by the CD4 gene.^[6][7]

CD4+ T helper cells are white blood cells that are an essential part of the human immune system. They are often referred to as CD4 cells, T helper cells or T4 cells. They are called helper cells because one of their main roles is to send signals to other types of immune cells, including CD8 killer cells, which then destroy the infectious particle. If CD4 cells become depleted, for example in untreated HIV infection, or following immune suppression prior to a transplant, the body is left vulnerable to a wide range of infections that it would otherwise have been able to fight.