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


METHODS
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.


CONCLUSIONS
These results suggest that Gi alpha is regulated and may be implicated in cAMP-dependent events during the terminal differentiation of human trophoblasts.
Daiter
E
E
Department of Obstetrics and Gynecology and Center for Research in Women's Health and Reproduction, University of Pennsylvania Medical Center, Philadelphia 19104, USA.
Makrigiannakis
A
A
Coukos
G
G
Woolkalis
M J
MJ
Coutifaris
C
C
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D001345:Autoradiography; D002454:Cell Differentiation; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D046508:Culture Techniques; D019084:Fluorescent Antibody Technique, Indirect; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000032:analysis* / Q000378:metabolism*; D006801:Humans; D009243:NAD / Q000378:metabolism; D013997:Time Factors; D014327:Trophoblasts / Q000737:chemistry / Q000502:physiology*
D009243:NAD; D000246:Adenosine Diphosphate Ribose; D019206:GTP-Binding Protein alpha Subunits, Gi-Go