Sandbox Reserved 954: Difference between revisions

The SCCA may play a role of cellular receptor for hepatitis B virus. The SCCA expression enhances the binding and internalization of hepatitis B virus with hepatocyte or non-hepatocytes origin cells. The transfection of SCCA in hepatocyte generates more viruses DNA in infected cells. Besides the virus bound to transfected cell is protected against degradation by trypsin thanks to a partial internalization. The binding between HBV and hepatocytes is more marked than for the others types of cells like COS-7 (kidney cells of monkey transformed by antibody T of SV40). The binding complex of cells COS-7 with HBV seems to be more complex. The low density lipoprotein receptor-related protein (LRP) mediates the clearance of serpin-enzyme complex, the LRP may not enhance virus binding to transfected cells. SCCA may be a co-receptor for HBV, virus binding to the transfected cells doesn’t depend on the proteinase inhibitor function or the interaction receptor LRP but it may depend on <scene name='60/604473/The_rcl_loop_scene/3'>the reactive site loop</scene> of SCCA. <ref>Penelope L. Moore‡, Sarah Ong, and Tim J. Harrison§, Squamous Cell Carcinoma Antigen 1-mediated Binding of Hepatitis B Virus to Hepatocytes Does Not Involve the Hepatic Serpin Clearance System*[http://www.jbc.org/content/278/47/46709.full DOI 47/46709.full]</ref>

SCCA1 also acts as an inhibitor of UV-induced apoptosis via suppression of the activity of c-Jun NH(2)-terminal kinase (JNK1). It is known that JNK1 is responsible for UV-induced apoptotic cell death and SCCA-1 is up-regulated in UV-irradiated and sun-exposed cells. SCCA1 binds to phosphorylated JNK1 and is transferred into the nucleus after UV irradiation.