CENTB1

CENTB1, also known as ACAP1, is composed of several distinct domains. Its structure includes an Arf-GAP domain with coiled-coil region, along with an ankyrin (ANK) repeat and a pleckstrin homology (PH) domain-containing protein. As for its quaternary structure, the CENTB1 protein has a banana-structure homodimer configuration. These homodimers laterally assemble into tetramers, which further pack helically onto the membrane. == Interactions ==

CENTB1 interacts with GTP-bound ARF6, regulating polymerization of the actin cytoskeleton around the plasma membrane. CENTB1 may also function as an adaptor protein by binding to clathrin heavy chain, linking specific cargo to the clathrin coat during the formation of a vesicle. == Function ==

CENTB1 is a cytoplasmic protein that is able to down-regulate the NF-κB activity through NOD-1 and NOD-2 signaling pathways. Which can be in response to γ-D-glutamyl-meso-diaminopimelic acid (iE-DAP) and muramyl dipeptide (MDP-LD) stimulation in intestinal epithelial cells. CENTB1 is a component of a novel clathrin coat complex involved in endocytic recycling, with initial evidence from studies in HeLa cells. ==Regulation==

With the regulation of ARF6, the CENTB1 containing clathrin coat complex functions in two physiological contexts requiring endocytic recycling. Which is integrin recycling, vital for cell migration, and Glut4 recycling, essential for glucose homeostasis. As well, CENTB1 facilitates TfR recycling and establishes its role in cargo sorting. It was also found that CENTB1 is a component of a novel clathrin coat complex that regulates stimulation-dependent integrin recycling and insulin-stimulated Glut4 recycling. == Clinical significance ==

CENTB1 was found to be an example of a protein that was initially characterized in human neutrophils. CENTB1 could be regarded as beneficial in treating chronic inflammatory disorders dominated by neutrophils, by functioning as a specific modulator of NF-κB activity. Ulcerative colitis CENTB1 gene and protein expression were investigated in patients with ulcerative colitis (UC). CENTB1 gene expression was measured from colonic biopsies of UC patients and was detected by using immunohistochemistry. Its findings indicated that the expression of CENTB1 gene was significantly up-regulated in colonic mucosa from patients with active UC compared to remission UC and the healthy patients. CENTB1 cells were primarily localized within inflammatory infiltrates and dominated by polymorphonuclear cells. As well, extending from the adventitia to the mucosa, with higher abundance observed in epithelial cells and the adventitia. Therefore, it suggest that CENTB1 is involved in the inflammatory process in patients with UC. == References ==