TY - JOUR
T1 - Requirement of ADP-ribosylation for the pertussis toxin-induced alteration in electrophoretic mobility of G-proteins
AU - Roerig, Sandra C.
AU - Loh, Horace H
AU - Law, Ping-Yee
PY - 1991/11/14
Y1 - 1991/11/14
N2 - Pertussis toxin (PTX) catalyzes the ADP-ribosylation of the α-subunit of GTPbinding proteins (G-proteins) in the presence of NAD+. Pertussis toxin also decreases the electrophoretic mobility of the a-subunit on urea SDS PAGE. This effect of PTX has been suggested to be a property of the toxin different from its ability to catalyze ADP-ribosylation. However, the present report provides evidence to the contrary; ie, this mobility shift required the ADP-ribosylation of α-subunits. This conclusion was based on: (1) in the presence of increasing concentrations of NAD+ (0.026-1.3 μM), there was a linear increase in the formation of the slower migrating α-subunit as measured by immunoblotting with selective antisera, (2) addition of NADase to the incubation mixture completely eliminated the formation of this protein, and (3) increasing concentrations of nicotinamide (50-250 mM), which inhibits ADP-ribosylation, decreased the amount of the slower migrating a-subunit. Thus, in addition to PTX, NAD+ was required for the mobility shift and the slower migrating a-subunit is likely the ADP-ribosylated form.
AB - Pertussis toxin (PTX) catalyzes the ADP-ribosylation of the α-subunit of GTPbinding proteins (G-proteins) in the presence of NAD+. Pertussis toxin also decreases the electrophoretic mobility of the a-subunit on urea SDS PAGE. This effect of PTX has been suggested to be a property of the toxin different from its ability to catalyze ADP-ribosylation. However, the present report provides evidence to the contrary; ie, this mobility shift required the ADP-ribosylation of α-subunits. This conclusion was based on: (1) in the presence of increasing concentrations of NAD+ (0.026-1.3 μM), there was a linear increase in the formation of the slower migrating α-subunit as measured by immunoblotting with selective antisera, (2) addition of NADase to the incubation mixture completely eliminated the formation of this protein, and (3) increasing concentrations of nicotinamide (50-250 mM), which inhibits ADP-ribosylation, decreased the amount of the slower migrating a-subunit. Thus, in addition to PTX, NAD+ was required for the mobility shift and the slower migrating a-subunit is likely the ADP-ribosylated form.
UR - http://www.scopus.com/inward/record.url?scp=0025787761&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025787761&partnerID=8YFLogxK
U2 - 10.1016/S0006-291X(05)81327-0
DO - 10.1016/S0006-291X(05)81327-0
M3 - Article
C2 - 1835388
AN - SCOPUS:0025787761
SN - 0006-291X
VL - 180
SP - 1227
EP - 1232
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -