The AE2 anion exchanger is necessary for the structural integrity of the Golgi apparatus in mammalian cells

FEBS Letters

Egea, Gustavo¹  Muñoz, Maria Teresa¹  Holappa, Katja²  Kellokumpu, Sakari² 

[1] Departament de Biologia Cel.lular i Anatomia Patològica, Facultat de Medicina, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, 08036 Barcelona, Spain;Department of Biochemistry, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland

关键词: Golgi apparatus;    Anion exchange;    pH;    Cytoskeleton;    Spectrin;    Microtubule;    ER;    endoplasmic reticulum;    AE2;    anion exchanger 2;    MTOC;    microtubule-organizing center;   

DOI  :  10.1016/S0014-5793(04)00315-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The structural integrity of the Golgi apparatus is known to be dependent on multiple factors, including the organizational status of microtubules, actin and the ankyrin/spectrin-based Golgi membrane skeleton, as well as vesicular trafficking and pH homeostasis. In this respect, our recently identified Golgi-associated anion exchanger, AE2, may also be of importance, since it potentially acts as a Golgi pH regulator and as a novel membrane anchor for the spectrin-based Golgi membrane skeleton. Here, we show that inhibition (>75%) of AE2 expression by antisense oligonucleotides in COS-7 cells results in the fragmentation of the juxtanuclear Golgi apparatus and in structural disorganization of the Golgi stacks, the cisternae becoming generally shorter, distorted, vesiculated and/or swollen. These structural changes occurred without apparent dissociation of the Golgi membrane skeletal protein Ankyrin₁₉₅, but were accompanied by the disappearance of the well-focused microtubule-organizing center (MTOC), suggesting the involvement of microtubule reorganization. Similar changes in Golgi structure and assembly of the MTOC were also observed upon transient overexpression of the EGFP-AE2 fusion protein. These data implicate a clear structural role for the AE2 protein in the Golgi and in its cytological positioning around the MTOC.

【 授权许可】

Unknown