LD78-beta/CCL3L1 Human Active Protein

This gene is one of several cytokine genes clustered on the q-arm of chromosome 17. Cytokines are a family of secreted proteins involved in immunoregulatory and inflammatory processes. This protein binds to several chemokine receptors including chemokine binding protein 2 and chemokine (C-C motif) receptor 5 (CCR5). CCR5 is a co-receptor for HIV, and binding of this protein to CCR5 inhibits HIV entry. The copy number of this gene varies among individuals; most individuals have 1-6 copies in the diploid genome, although rare individuals have zero or more than six copies. The human genome reference assembly contains two full copies of the gene (CCL3L3 and CCL3L1) and a partial pseudogene. This record represents the more centromeric full-length gene. [provided by RefSeq, Apr 2010]

Function: Chemotactic for lymphocytes and monocytes. Is a ligand for CCR1, CCR3 and CCR5. Is an inhibitor of HIV-1-infection. The processed form LD78-beta(3-70) shows a 20-fold to 30-fold higher chemotactic activity and is a very potent inhibitor of HIV-1-infection. LD78-beta(3-70) is also a ligand for CCR1, CCR3 and CCR5. Ref.7 Ref.8

Subcellular location: Secreted.

Post-translational modification: The N-terminal processed forms LD78-beta(3-70) and LD78-beta(5-70) are produced by proteolytic cleavage after secretion from peripheral blood monocytes. The cleavage to yield LD78-beta(3-70) is probably achieved by DPP4.

Polymorphism: The copy number of the CCL3L1 gene varies among individuals; most individuals have 1-6 copies in the diploid genome, although rare individuals have zero or more than 6 copies.

Sequence similarities: Belongs to the intercrine beta (chemokine CC) family.