|Detection of Human BASP1 by Western Blot. Western blot shows lysates of HeLa human cervical epithelial carcinoma cell line and DU145 human prostate carcinoma cell line. PVDF Membrane was probed with 1 µg/mL of Human BASP1 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF6479) followed by HRP-conjugated Anti-Sheep IgG Secondary Antibody (Catalog # HAF016). A specific band was detected for BASP1 at approximately 60 kDa, possibly a higher molecular weight isoform or a product of SUMOyation. Lower molecular weight isoforms were also observed. This experiment was conducted under reducing conditions on a 4-20% SDS-PAGE gel and using Immunoblot Buffer Group 1.|
BASP1 (Brain acid soluble protein 1; also NAP-22) is a transcriptional cosuppressor that belongs to the BASP1 family of proteins. Although its predicted MW is 23 kDa, BASP1 will show multiple bands in SDS-Page. First, BASP1 forms oligomers in SDS, ranging in size from 30-150 kDa. Second, varying concentrations of SDS will change the apparent BASP1 MW from 56 kDa in 8% SDS-Page to 41 kDa in 13% SDS-Page. At least two forms of BASP1 apparently exist in human, one that is 48-52 kDa, and another that is 32-40 kDa in size. They are not functionally equivalent. BASP1 can be SUMOylated that add 20 kDa in apparent MW. There are also N-terminal fragments termed BIRPs that run from 30-50 kDa in 12% acidic SDS-Page. BASP1 is expressed in neurons, renal podocytes and spermatids. It binds to the cytoplasmic side of the plasmalemma via its myristroylate adduct, and undergoes nuclear translocation when SUMOylated. Human BASP1 is 227 amino acids (aa) in length. It contains a myristoylation site at Gly2, SUMOylation sites at Lys79 and 84, at least eight utilized phosphorylation sites, and an NLS. One splice variant shows a deletion of aa 88-141. Over aa 1-45, human BASP1 shares 96% and 91% aa identity with mouse and rat BASP1, respectively.