Cross-linking of G-proteins to the prolactin receptor in rat NB2 lymphoma cells.
In Nb2 cell membranes, two guanine nucleotide-binding protein (G-protein) species (Mr 43.5 and 46.5 kD) were [32P]-ADP-ribosylated by cholera toxin, while a single protein (Mr 41.5 kD) was [32P]-ADP-ribosylated by pertussis toxin. Immunostaining indicated two immunoreactive prolactin (PRL) receptor moieties of 56 and 64 kD. Cross-linking with ethylene glyco bis[succinimidyl-succinate] (mol. length of 16.1 A) generated a high mol. wt., [32P]-ADP-ribosylated band of 140-160 kD which also showed immunoreactivity with antiserum to the PRL receptor. Other cross-linkers with shorter molecular lengths (8.6 - 11.4 A) were ineffective. These findings indicate that the Nb2 lactogen receptor is complexed with G-proteins and provide evidence for the role of G-proteins in mediating PRL-stimulated mitognesis in Nb2 cells.
Too
C K
CK
Dept. of Physiology, University of Manitoba, Winnipeg, Canada.
Shiu
R P
RP
Friesen
H G
HG
D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002772:Cholera Toxin / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D019204:GTP-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008223:Lymphoma; D008970:Molecular Weight; D037342:Pertussis Toxin; D051381:Rats; D011981:Receptors, Prolactin / Q000302:isolation & purification / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000378:metabolism
D003432:Cross-Linking Reagents; D011981:Receptors, Prolactin; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D002772:Cholera Toxin; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins