TY - JOUR
T1 - Identification of G-proteins in rat parotid gland plasma membranes and granule membranes
T2 - presence of distinct components in granule membranes
AU - Ali, Nawab
AU - Agrawal, Devendra K.
AU - Cheung, Peter
PY - 1992/10
Y1 - 1992/10
N2 - We have identified by immunoblotting and ADP-ribosylation by cholera toxin and pertussis toxin the presence of Mr 43 and 46 KDa Gsα, and 39 and 41 KDa Giα;.. subunits in rat parotid gland plasma membranes but not in granule membranes. A Mr 28 KDa polypeptide that served as substrate for ADP-ribosylation by both cholera toxin and pertussis toxin was present exclusively in granule membranes. Photoaffinity crosslinking of [α-32P]GTP showed the presence of high molecular weight GTP-binding proteins (Mr 160,100 KDa) in granule membranes. Six low molecular weight GTP-binding proteins (Mr 21-28 KDa) were differentially distributed in both plasma membranes and granule membranes. The present study identifies various GTP-binding proteins in rat parotid gland plasma membranes and granule membranes, and demonstrates the presence of distinct molecular weight GTP-binding proteins in granule membranes. These granule-associated GTP-binding proteins may be involved in secretory processes.
AB - We have identified by immunoblotting and ADP-ribosylation by cholera toxin and pertussis toxin the presence of Mr 43 and 46 KDa Gsα, and 39 and 41 KDa Giα;.. subunits in rat parotid gland plasma membranes but not in granule membranes. A Mr 28 KDa polypeptide that served as substrate for ADP-ribosylation by both cholera toxin and pertussis toxin was present exclusively in granule membranes. Photoaffinity crosslinking of [α-32P]GTP showed the presence of high molecular weight GTP-binding proteins (Mr 160,100 KDa) in granule membranes. Six low molecular weight GTP-binding proteins (Mr 21-28 KDa) were differentially distributed in both plasma membranes and granule membranes. The present study identifies various GTP-binding proteins in rat parotid gland plasma membranes and granule membranes, and demonstrates the presence of distinct molecular weight GTP-binding proteins in granule membranes. These granule-associated GTP-binding proteins may be involved in secretory processes.
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U2 - 10.1007/BF00230326
DO - 10.1007/BF00230326
M3 - Article
C2 - 1280320
AN - SCOPUS:0026461030
VL - 115
SP - 155
EP - 162
JO - Molecular and Cellular Biochemistry
JF - Molecular and Cellular Biochemistry
SN - 0300-8177
IS - 2
ER -