Nuclear pore complex glycoprotein p62 of Xenopus laevis and mouse: cDNA cloning and identification of its glycosylated region

Abstract

cDNA clones for nuclear pore complex glycoprotein p62 of two distantly related species, mouse and Xenopus laevis, were isolated. Antibodies raised against recombinant murine p62 react on protein blots with p62 of both species and decorate pore complexes. Analysis of the predicted protein sequence indicates that vertebrate p62 is organized into two structurally different regions. The entire carboxy-terminal half (86.7% identical amino acids) and the amino-terminal 56 amino acids (62.5% identity) have been highly conserved during evolution. The amino-terminal half contains several penta amino acid repeats and is able to form beta-sheets, whereas the carboxy-terminal half is predominantly organized in alpha-helical structures in part with heptad repeats typical for intermediate filament proteins. p62 of mouse and Xenopus is glycosylated by N-acetylglucosamine additions in the amino-terminal half. The region containing these potential glycosylation sites has been identified.