Ghitm is an ortholog of the Bombyx mori prothoracic gland-derived receptor (Pgdr) that is ubiquitously expressed in mammalian cells and requires an N-terminal signal sequence for expression

In a previous paper, we reported the cloning of a cDNA encoding a putative receptor, Pgdr, from the prothoracic gland of the silkworm, Bombyx mori. Few studies concerning the orthologous cDNA of Pgdr in mammals, a growth hormone-inducible transmembrane protein (Ghitm) that encodes a putative receptor, have been performed. Analysis of the distribution of Ghitm expression revealed ubiquitous expression in mouse embryo and adult tissues, as well as mammalian cell lines. The pattern of Ghitm expression suggested that once Ghitm mRNA was expressed in the putative brain region of mouse embryo, Ghitm-expressing cells spread ubiquitously throughout all tissues during embryonic development. In addition, Western blot analyses demonstrated that cleavage of the N-terminal portion in GHITM appears to regulate the expression level, suggesting that cleavage is essential for the proper expression of GHITM.