A phorbol ester‐binding protein is required downstream of Rab5 in endosome fusion

FEBS Letters

Mayorga, Luis S²  Arenas, Graciela N²  Barbieri, M.Alejandro¹  Aballay, Alejandro²  Colombo, Marı́a I¹  Stahl, Philip D¹ 

[1]Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA

[2]Instituto de Histologı́a y Embriologı́a, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo – CONICET, Casilla de correo 56, 5500 Mendoza, Argentina

关键词: Endosome fusion;    Endocytosis;    Protein kinase C;    Phorbol ester;    Rab5;    BSA;    bovine serum albumin;    CPC;    calphostin C;    DAG;    diacylglycerol;    PA;    phorbol 13-monoacetate;    PMA;    phorbol 12-myristate 13-acetate;    GST-Rab5 proteins;    glutathione S-transferase fusion proteins;    TPEN;    N;    N;    N′;    N′-tetrakis-(2-pyridylmethyl)ethylenediamine;   

DOI  :  10.1016/S0014-5793(98)01579-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Previous observations indicate that a zinc and phorbol ester binding factor is necessary for endosome fusion. To further characterize the role of this factor in the process, we used an in vitro endosome fusion assay supplemented with recombinant Rab5 proteins. Both zinc depletion and addition of calphostin C, an inhibitor of protein kinase C, inhibited endosome fusion in the presence of active Rab5. Addition of the phorbol ester PMA (phorbol 12-myristate 13-acetate) reversed the inhibition of endosome fusion caused by a Rab5 negative mutant. Moreover, PMA stimulated fusion in the presence of Rab5 immunodepleted cytosol. These results suggest that the phorbol ester binding protein is acting downstream of Rab5 in endosome fusion.

【 授权许可】

Unknown