BRAK Human

BRAK, also known as CXCL14, is a member of the CXC chemokine family. Chemokines are small cytokines or signaling proteins secreted by cells, and they play a crucial role in immune responses by directing the movement of circulating leukocytes to sites of inflammation or injury. CXCL14 is unique among chemokines due to its distinct expression pattern and functions.

BRAK (CXCL14) was initially identified in normal tissues, particularly in the breast and kidney, hence its name “Breast and Kidney-expressed Chemokine” (BRAK) . It is also known by several other names, including Bolekine, MIP-2 gamma, and Small-inducible cytokine B14 .

CXCL14 is a 9.4 kDa protein consisting of 77 amino acid residues . It is characterized by the presence of two cysteines separated by a single amino acid, a hallmark of the CXC chemokine family . Unlike many other chemokines, CXCL14 is expressed in normal tissues in the absence of inflammatory stimuli and is infrequently expressed in cancer cell lines .

CXCL14 exhibits chemotactic activity, particularly for monocytes, but not for lymphocytes, dendritic cells, neutrophils, or macrophages . This suggests that CXCL14 may play a role in the homeostasis of monocyte-derived macrophages rather than in inflammation . Additionally, CXCL14 has been shown to have antimicrobial activity, which is attributed to its amphipathic cationic alpha-helical region in the C-terminus .

CXCL14 is implicated in various physiological and pathological processes. It is highly expressed in tumor-associated stromal cells, promoting tumor cell growth and invasion . Dysregulated expression of CXCL14 has been associated with chronic periodontitis and liver diseases . Furthermore, CXCL14 is an effective angiogenesis inhibitor and has potential therapeutic applications in cancer treatment due to its ability to inhibit tumor growth and metastasis .

Recombinant human CXCL14 is produced using an E. coli expression system . It is available in a lyophilized form and is used in various research applications, including Western Blot (WB), ELISA, and functional assays . The recombinant protein is highly purified, with a purity of ≥ 98% as determined by SDS-PAGE and HPLC analyses .