TY - JOUR
T1 - Identification of guanine nucleotide binding regulatory proteins in bovine tracheal smooth muscle
AU - Joshi, Sharmishtha
AU - Abebe, Worku
AU - Agrawal, Devendra K.
PY - 1996
Y1 - 1996
N2 - The identity of G-proteins in airway smooth muscle is not well elucidated. In the present study, by immunoblotting using AS/7 antibody specific for G(iα-1/2), EC/2 antibody specific for G(iα-3) and RM/1 antibody specific for G(sα), we identified, respectively, Mr 39, 41, 46 and 52 KDa, Mr 41 and 43 KDa, and Mr 43 and 46 KDa polypeptides of conventional (heterotrimeric) G-proteins in purified membranes of bovine tracheal smooth muscle. The identity of the Mr 41, 43 and 52 KDa G(iα), and the Mr 43 and 46 G(sα) was also confirmed by ADP-ribosylation with pertussis and cholera toxins, respectively. In addition, the common antibody (AG/1) for both G(iα) and G(sα) revealed the presence of all the above polypeptides, except the Mr 52 KDa band. By nitrocellulose blot overlay with [35S]GTPγS, we also detected seven low molecular weight GTP-binding proteins of Mr 18-30 KDa in the bovine tracheal smooth muscle. Photoaffinity crosslinking of [α-32P]GTP demonstrated the presence of high molecular GTP-binding proteins of Mr 55, 75 and 110 KDa. It is concluded that plasma membranes of bovine tracheal smooth muscle contain various types of conventional, low molecular weight and high molecular weight G-proteins. This warrantes further attention to elucidate the functional roles of G-proteins in airway smooth muscle.
AB - The identity of G-proteins in airway smooth muscle is not well elucidated. In the present study, by immunoblotting using AS/7 antibody specific for G(iα-1/2), EC/2 antibody specific for G(iα-3) and RM/1 antibody specific for G(sα), we identified, respectively, Mr 39, 41, 46 and 52 KDa, Mr 41 and 43 KDa, and Mr 43 and 46 KDa polypeptides of conventional (heterotrimeric) G-proteins in purified membranes of bovine tracheal smooth muscle. The identity of the Mr 41, 43 and 52 KDa G(iα), and the Mr 43 and 46 G(sα) was also confirmed by ADP-ribosylation with pertussis and cholera toxins, respectively. In addition, the common antibody (AG/1) for both G(iα) and G(sα) revealed the presence of all the above polypeptides, except the Mr 52 KDa band. By nitrocellulose blot overlay with [35S]GTPγS, we also detected seven low molecular weight GTP-binding proteins of Mr 18-30 KDa in the bovine tracheal smooth muscle. Photoaffinity crosslinking of [α-32P]GTP demonstrated the presence of high molecular GTP-binding proteins of Mr 55, 75 and 110 KDa. It is concluded that plasma membranes of bovine tracheal smooth muscle contain various types of conventional, low molecular weight and high molecular weight G-proteins. This warrantes further attention to elucidate the functional roles of G-proteins in airway smooth muscle.
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U2 - 10.1007/BF00226786
DO - 10.1007/BF00226786
M3 - Article
C2 - 8717432
AN - SCOPUS:0030030845
VL - 154
SP - 179
EP - 184
JO - Molecular and Cellular Biochemistry
JF - Molecular and Cellular Biochemistry
SN - 0300-8177
IS - 2
ER -