[gamma]-Adducin Promotes Process Outgrowth and Secretory Protein Exit from the Golgi Apparatus

• Published in: Journal of molecular neuroscience 2013-01, Vol.49 (1), p.1
• Main Authors: Lou, Hong, Park, Joshua J, Phillips, Andre, Loh, Y Peng
• Format: Article
• Language: English
• Subjects: Amino acids; Antibodies; Kinases; Localization; Neurosciences; Proteins; Roles
• ISSN: 0895-8696; 1559-1166
• DOI: 10.1007/s12031-012-9827-0

[alpha], [beta], and γ adducins mediate F-actin remodeling of plasma membrane structures as heterotetramers. Here, we present two new functions of γ-adducin. (1) Overexpression of γ-adducin promoted formation of neurite-like processes in non-neuronal fibroblast COS7 cells. Conversely, overexpression of the C-terminal 38 amino acids of γ-adducin (γAdd^sub C38^) acting as a dominant negative inhibited formation of neurites/processes in Neuro2A cells and anterior pituitary AtT20 cells. (2) γ-Adducin appears to facilitate pro-opiomelanocortin (POMC) exit from the trans-Golgi network (TGN) by re-organizing the actin network around the Golgi complex. Filamentous actins (F-actins) which formed puncti around the Golgi complex in control cells were dispersed in AtT20 cells stably transfected with γAdd^sub C38^. Furthermore, γAdd^sub C38^-transfectants showed significant accumulation of POMC/adrenocorticotropin (ACTH) in the Golgi complex and diminished POMC/ACTH vesicles in the cell processes. The C-terminal 38 amino acids of γ-adducin interacted with F-actins around the Golgi complex, to facilitate F-actin-mediated budding of POMC/ACTH vesicles from the TGN. Thus, we propose that γ-adducin, via its interaction with F-actins, plays a critical role in actin remodeling to facilitate process/neurite outgrowth, as well as budding of POMC/ACTH vesicles from the TGN via its interaction with peri-Golgi F-actins.[PUBLICATION ABSTRACT]