Small GTP-Binding Proteins on Rat Liver Lysosomal Membranes

Cell Structure and Function

Shoji Ohkuma¹  Yoshimichi Sai¹ 

[1] Department of Biochemistry, Faculty of Pharmaceutical Sciences, Kanazawa University

关键词: GTP-binding protein;    lysosome;    ras;   

DOI  :  10.1247/csf.17.363

学科分类：分子生物学，细胞生物学和基因

来源: Japan Society for Cell Biology

【 摘 要 】

References(39)Cited-By(5)GTP-binding proteins have been identified on the membranes of highly purified dextran-filled lysosomes (dextranosomes) and Triton-filled lysosomes (tritosomes) obtained from rat liver. Autoradiography of blots of lysosomal membrane proteins incubated with [α-32P]GTP revealed the presence of several specific GTP-binding proteins with a relative molecular mass (Mr) predominantly in the range of 26-30 kDa. These GTP-binding proteins migrated slower in polyacrylamide gels than purified c-Ha-ras protein expressed in E. coli, whose apparent Mr was 23 kDain the same blot. The relative contents of GTP-binding proteins in lysosomal membranes were comparable or greater than that of plasma membranes and of microsomes. Chemical extraction showed that lysosomal GTP-binding proteins were more tightly associated with the membranes than with microsomal GTP-binding proteins. The possible involvement of lysosomal GTP-binding proteins in cellular functions including vacuolar (lysosomal) acidification and organellar dynamics are discussed.

【 授权许可】

Unknown