BRAK

BRAK/CXCL14 (breast and kidney-expressed chemokine), also named MIP2 gamma, KEC (kidney-expressed chemokine), and BMAC (B cell and monocyteactivating chemokine), is a member of CXC chemokine superfamily. The deduced 99 amino acid (aa) residue precursor has a 22 aa putative signal peptide that is cleaved to produce the 77 aa mature protein. Mature human and mouse CXCL14 differ by only 2 residues. Human CXCL14 shares approximately 30% aa sequence identity with MIP2α (GROβ) as well as MIP2β (GROγ). The gene for CXCL14 has been mapped human chromosome 5q31. Unlike the MIP2 chemokines, CXCL14 lacks the ELR domain preceding the CXC motif. CXCL14 transcripts are constitutively expressed at high levels in the basal layer of epidermal keratinocytes and dermal fibroblasts of skin tissues as well as lamina propria cells in normal intestinal tissues. CXCL14 has been shown to be a highly selective chemoattractant for monocytes that have been treated with prostaglandin E 2 or forskolin, agents that activate adenylate cyclase. CXCL14 has been proposed to be important for regulating the trafficking of macrophage precursor to regions in skin and mucosal tissues that support their development. Consistent with this hypothesis, macrophages were frequently found to colocalize with CXCL14producing cells in the dermis and lamina propria.