| Primary Identifier | IPR003566 | Type | Family |
| Short Name | Tcell_CD5 |
| description | The egg peptide speract receptor is a transmembrane glycoprotein of about500 amino acids []. Topologically, it comprises a large extracellulardomain of about 450 residues, followed by a transmembrane domain and ashort cytoplasmic region of about 12 amino acids. The extracellulardomain contains 4 repeats of a well-conserved region, which spans 115amino acids and contains 6 conserved cysteines. A similar domain is alsofound towards the C terminus of macrophage scavenger receptor type I [],a membrane glycoprotein implicated in the pathologic deposition ofcholesterol in arterial walls during artherogenesis, and in the CD5glycoprotein, which acts as a receptor in regulating T-cell proliferation.The T1/Leu-1/CD5 glycoprotein is expressed at the surface membrane of allmature T cells. It has been implicated both in the proliferative response of activated T cells and in T-cell helper function []. Thecomplete amino-acid sequence of the T1 precursor has been deduced from cDNAclones. The protein contains a classical signal peptide; a 347-residue extracellular segment; a transmembrane region; and a 93-residue intra-cellular segment []. The extracellular region contains several cysteineresidues and comprises 2 speract receptor domains separated by a proline/threonine-rich region []. CD5 has been shown to function as a receptor,delivering co-stimulatory signals to T-cells, interacting specifically withthe cell-surface protein CD72 (Lyb-2 in mice) exclusive to B-cells []. |
