Synthetic peptides of the effector‐binding domain of rab enhance secretion from digitonin‐permeabilized chromaffin cells

FEBS Letters

Balch, William E.¹  Holz, Ronald W.²  Senyshyn, Jan² 

[1] Department of Molecular Biology, Research Institute of Scripps Clinic, La Jolla, CA 92037, USA;Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI 48109-0626, USA

关键词: rab Peptide;    Exocytosis;    Chromaffin cell;    Calcium;    Guanine nucleotide;    ER;    endoplasmic reticulum;    GppNHp;    guanosine 5′-(β;    γ-imido)triphosphate;    KGEPM;    potassium glutamate;    EGTA-;    PIPES-;    MgCl2-;    MgATP- and bovine serum;    albumin-containing medium;    PKC;    protein kinase C;    PSS;    physiological salt solution;   

DOI  :  10.1016/0014-5793(92)80735-Y

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

There is evidence that the rab class of low molecular weight GTP-binding proteins is involved in vesicular transfer from endoplasmic reticulum to Golgi and between Golgi cisternae. To determine whether similar proteins play a role in regulated exocytosis, the effects of synthetic peptides derived from low molecular weight GTP-binding proteins on catecholamine secretion from digitonin-permeabilized chromaffin cells were investigated. The synthetic peptides represent the putative effector-binding domains of the rab, ras and ral classes of low molecular weight GTP-binding proteins and correspond to ras(33–48). Two rab peptides but neither a ras nor a ral peptide enhanced Ca²⁺-dependent secretion by approximately 30%. Maximal secretion in response to Ca²⁺ was increased. The enhancement was not blocked by the pseudosubstrate inhibitor of protein kinase C, PKC(19–31), thus indicating that activation of protein kinase C was not responsible for the enhancement of secretion. Similarly a rab peptide but neither a ras nor a ral peptide enhanced CppNHp-induced secretion 30–70%. The peptides had little or no effet in the absence of Ca²⁺ or GppNHp. The data are consistent with a protein of the rab class playing a role in regulated exocytosis.

【 授权许可】

Unknown