Localization of a low Mr GTP-binding protein, rap1 protein, in plasma membranes and secretory granule membranes of rat parotid gland.
Subcellular fractions were prepared from rat parotid gland by sequential centrifugation, Percoll gradient centrifugation and divalent-cation precipitation, and the localization of a low Mr GTP-binding protein, rap1 protein (rap1p) was analyzed by immunoblotting using a specific antibody. rap1p was found to be located in apical and basolateral plasma membranes, and secretory granule membranes in rat parotid gland. On the other hand, the beta gamma subunits of heterotrimeric Gt protein was localized in plasma membranes but not in granule membranes.
Kameyama
Y
Y
Department of Oral Biochemistry, Asahi University School of Dentistry, Gifu, Japan.
Nagata
K
K
Mizuno-Kamiya
M
M
Yokota
Y
Y
Fujita
A
A
Nozawa
Y
Y
D000818:Animals; D002458:Cell Fractionation; D002462:Cell Membrane / Q000737:chemistry; D003594:Cytoplasmic Granules / Q000737:chemistry*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D015151:Immunoblotting; D008297:Male; D008970:Molecular Weight; D010306:Parotid Gland / Q000737:chemistry* / Q000648:ultrastructure; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D013347:Subcellular Fractions / Q000378:metabolism; D020668:rap GTP-Binding Proteins; D020827:rap1 GTP-Binding Proteins / Q000032:analysis* / Q000378:metabolism
D016244:Guanosine 5'-O-(3-Thiotriphosphate); C000620839:Rap1 protein, mouse; D020668:rap GTP-Binding Proteins; D020827:rap1 GTP-Binding Proteins