Molecular characterization and 3D Modeling of p62 in Grass Carp (Ctenopharyngodon Idella)

Abstract

P62 is a ubiquitin-binding protein that plays a key role in biological pathways including autophagy and protein degradation. In this study, we analyzed the protein sequence of grass carp p62 (gcp62) and its 3D structure was predicated. The full-length cDNA of gcp62 was 1425 bp, and encoded a 474-aa protein. Multiple sequence alignment analysis showed that gcp62 shared 40.82~41.80% amino acid identities with its orthologues of human, mouse and tropical clawed frog, as well as relatively high identities (63.28 and 78.71% respectively) with yellow catfish and zebrafish p62. The phylogenetic analysis showed that gcp62 has close relationship with its orthologues in common carp and zebrafish, but differs from its homologs in mammalian species. Like in mammals, gcp62 was predicted to contain three conserved domains, the N-terminal Phox and Bem1p (PB1) domain, the ZZ domain and the C-terminal ubiquitin-associated (UBA)domain. This is the first time to construct the 3D structure of fish p62 and the high similarity of p62 structure between human and fish indicates the functional conservation in vertebrates.