Recombinant Human HRP-2 Isoform 1 Protein, CF

Hepatoma-derived growth factor (HDGF)-related protein 2 (HRP-2) is a 74 kDa (predicted) member of the HDGF protein family (1 - 5). Similar to the electrophoretic mobility of HRP-3, HRP-2 runs as an anomalously large molecule in SDS-PAGE (4, 5). Members of this gene family have a highly conserved 98 amino acid (aa) sequence at the amino terminus (hath region, for homologous to amino terminus of HDGF) (1). Human HRP-2 is 671 aa in length and has no conserved sequence other than the hath region (1). There is no putative signal peptide sequence for secretion. Located within the hath region is a PWWP domain (aa 5 - 76), named after a conserved Pro-Trp-Trp-Pro motif. The protein also contains a serine-rich region (aa 142 - 269), an arginine-rich region (aa 318 - 391), an HIV-1 Integrase binding domain (IBD) (aa 470-552), a coiled-coil region (aa 521 - 581), and 19 phosphoserine sites that are apparently utilized. There are two isoforms for HRP-2, named 1 and 2. Isoform 2 is missing Ser640 which is found in isoform 1. Human HRP-2 shares 81% and 80% aa sequence identity with mouse and rat HRP-2, respectively. HRP-2 mRNA is highly expressed in testis and skeletal muscle, and is known to exist in neurons, astrocytes and oligodendroglia (1, 5). Like other proteins with a PWWP domain, HRP-2 is imported into the nucleus where it may function as a regulatory protein (1 - 2). The phosphoprotein may also play a role in viral replication, as it has been shown to bind to HIV-Integrase and efficiently reconstitute the in vitro activity of HIV-1 preintegration complexes (2 - 3).