Expression analysis and characteristics of hypothetical protein BmLOC778500 from silkworm, <i>Bombyx mori</i>

Abstract

We cloned a cDNA from silkworm pupal cDNA library and found that, it encodes LOC778500 protein (a “hypothetical protein” in the National Center for Biotechnology Information (NCBI) database). Thus, we named it BmLOC778500 (Bombyx mori LOC778500). It contains an open reading frame of 489 bp encoding a polypeptide of 162 amino acid residues with a predicted molecular mass of 19.4 kDa. The gene codes for a protein homologous to hypothetical proteins of Tribolium castaneum, Pediculus humcorporisanus and Drosophila erecta among others. Purified BmLOC778500 was used to generate anti-BmLOC778500 polyclonal antibody for determining tissue distribution and sub-cellular localization of BmLOC778500. Western blotting analysis revealed that, BmLOC778500 proteins existed in Malpighian tubule of fifth-instar larva of B. mori. Immunostaining indicated that, BmLOC778500 proteins are mainly located in cytosol and nucleus as well as in not-dividing cells, whereas are distributed in cell membrane in dividing cells. These results have provided important information for further function studies of BmLOC778500 protein.

Key words: BmLOC778500, Bombyx mori, expression analysis, tissue distribution, sub-cellular localization.