Inhibitory G protein alpha subunit (Gi alpha) expression and localization during human trophoblast differentiation.

Overview

OBJECTIVE: Cyclic adenosine monophosphate (cAMP) participates in the regulation of processes associated with trophoblast syncytialization. As guanosine triphosphate (GTP)-binding regulatory proteins (G-proteins) modulate adenylate cyclase activity, the present study investigated the expression and regulation of the alpha subunit of inhibitory G protein (Gi alpha) during human trophoblast differentiation in vitro. STUDY DESIGN: Protein levels and the immunolocalization of the protein at a subcellular-level were assessed. RESULTS: Expression of Gi alpha protein decreased during syncytialization. Moreover, Gi alpha transmigrated from a predominantly cell membrane-associated to a predominantly perinuclear location during the process. CONCLUSION: These results suggest that Gi alpha is regulated and may be implicated in cAMP-dependent events during the terminal differentiation of human trophoblasts.