The regulation of actin polymerization in differentiating U937 cells correlates with increased membrane levels of the pertussis-toxin-sensitive G-protein Gi2.
Undifferentiated U937 cells appear to lack a capacity of increase cellular F-actin. However, electropermeabilized cells gain the ability to respond in this way to a guanine nucleotide analogue, guanosine 5'-[gamma-thio]trisphosphate (GTP[S]) after 1 h of treatment with dibutyryl cyclic AMP (db-cAMP). The results reported here show that the levels of membrane association of the G-protein Gi2 alpha increase with a time course identical with that of the GTP[S]-sensitivity of electropermeabilized cells. These results suggest that Gi2 alpha may be involved in the signal-transduction pathway leading to actin polymerization in db-cAMP-differentiated U937 cells.
Sheth
B
B
Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, U.K.
Banks
P
P
Burton
D R
DR
Monk
P N
PN
D000199:Actins / Q000378:metabolism*; D015153:Blotting, Western; D003994:Bucladesine / Q000494:pharmacology; D002454:Cell Differentiation; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D037342:Pertussis Toxin; D011108:Polymers / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D000199:Actins; D011108:Polymers; D010566:Virulence Factors, Bordetella; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D003994:Bucladesine; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins