Cluster Of Differentiation 5 (CD5)

T1; LEU1; Lymphocyte antigen T1/Leu-1

SPN	V042
HGNC	1685
MGI	88340
PubMed	10082557
RGD	2309
UniProt	P06127
Wiki	CD5_(protein

CD5 is a cluster of differentiation found on a subset of IgM-secreting B cells called B-1 cells, and also on T cells. B-1 cells have limited diversity of their B-cell receptor due to their lack of the enzyme terminal deoxynucleotidyl transferase (TdT) and are potentially self-reactive. CD5 serves to mitigate activating signals from the BCR so that the B-1 cells can only be activated by a very strong stimuli (such as bacterial proteins) and not by normal tissue proteins. CD5 was used as a T-cell marker until monoclonal antibodies against CD3 were developed. In humans, the gene is located on the long arm of chromosome 11. There is no confimed ligand for CD5. T cells express higher levels of CD5 than B cells. CD5 is upregulated on T cells upon strong activation.

Reference

"Isolation of complementary DNA clones encoding the human lymphocyte glycoprotein T1/Leu-1."
Nature 323:346-349(1986) [PubMed] [Europe PMC] [Abstract]

"Evolutionarily conserved transcription regulatory elements within the 5'-flanking region of the human CD5 gene."
Tissue Antigens 47:257-261(1996) [PubMed] [Europe PMC] [Abstract]

"Complete sequencing and characterization of 21,243 full-length human cDNAs."
Nat. Genet. 36:40-45(2004) [PubMed] [Europe PMC] [Abstract]

"Human chromosome 11 DNA sequence and analysis including novel gene identification."
Nature 440:497-500(2006) [PubMed] [Europe PMC] [Abstract]

"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)."
Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract]

"The B-cell surface protein CD72/Lyb-2 is the ligand for CD5."
Nature 351:662-665(1991) [PubMed] [Europe PMC] [Abstract]

"Profiling of tyrosine phosphorylation pathways in human cells using mass spectrometry."
Proc. Natl. Acad. Sci. U.S.A. 100:443-448(2003) [PubMed] [Europe PMC] [Abstract]

"Robust phosphoproteomic profiling of tyrosine phosphorylation sites from human T cells using immobilized metal affinity chromatography and tandem mass spectrometry."
Anal. Chem. 76:2763-2772(2004) [PubMed] [Europe PMC] [Abstract]

"Quantitative phosphoproteomic analysis of T cell receptor signaling reveals system-wide modulation of protein-protein interactions."
Sci. Signal. 2:RA46-RA46(2009) [PubMed] [Europe PMC] [Abstract]

"Crystal structure of the third extracellular domain of CD5 reveals the fold of a group B scavenger cysteine-rich receptor domain."
J. Biol. Chem. 282:12669-12677(2007) [PubMed] [Europe PMC] [Abstract]

"Three-dimensional solution structure and conformational plasticity of the N-terminal scavenger receptor cysteine-rich domain of human CD5."
J. Mol. Biol. 378:129-144(2008) [PubMed] [Europe PMC] [Abstract]