Association of a 24‐kDa GTP‐binding protein, Gn24, with human platelet α‐granule membranes

FEBS Letters

Bhullar, Rajinder P.²  van der Meulen, John¹  Chancellor-Maddison, Kerry-Ann¹ 

[1] Department of Pediatrics, McMaster University, Hamilton, Ontario L8N 3Z5, Canada;Department of Pathology, McMaster University, Hamilton, Ontario L8N 3Z5, Canada

关键词: Gn-protein;    GTP-binding protein;    Platelet;    α-Granule;    GTPγS;    guanosine 5′-[γ-thio]triphosphate;    Gn-proteins;    23-27-kDa proteins detected by binding of [α-32P]GTP to nitrocellulose blots [1];   

DOI  :  10.1016/0014-5793(91)81118-R

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Human platelets were disrupted using nitrogen cavitation and fractionated on sucrose density gradients to permit isolation of α-granules, the major secretory granule of platelets. Membrane proteins prepared from intact α-granules by alkali extraction were separated by SDS-polyacrylamide gel electrophoresis, transferred to nitrocellulose and the blot probed for the presence of GTP-binding proteins using [α-³²P]GTP. Two low molecular mass GTP-binding proteins with molecular mass of 27 and 24 kDa, respectively, were identified on the α-granule membrane. In contrast to the 27-kDa protein which was present in significant amounts in the plasma membrane-enriched fraction, the 24-kDa protein showed a preferential association with the α-granule membrane. On immunoblotting with specific antiserum, the 24-kDa GTP-binding protein was found to be distinct from rab3A. To the best of our knowledge, the present report represents the first identification of low molecular mass GTP-binding proteins associated with a platelet secretory granule.

【 授权许可】

Unknown