Surface expression of the Anoctamin-1 (ANO1) channel is suppressed by protein–protein interactions with β-COP

• Published in: Biochemical and biophysical research communications Vol. 475; no. 2; pp. 216 - 222
• Main Authors: Lee, Young-Sun, Bae, Yeonju, Park, Nammi, Yoo, Jae Cheal, Cho, Chang-Hoon, Ryoo, Kanghyun, Hwang, Eun Mi, Park, Jae-Yong
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 24-06-2016
• Subjects: ANO1; Anoctamin-1; Biological Transport; Brain Neoplasms - metabolism; Cell Line, Tumor; Cell Membrane - metabolism; Chloride Channels - metabolism; Coatomer Protein - analysis; Coatomer Protein - metabolism; Glioblastoma - metabolism; HEK293 Cells; Humans; Neoplasm Proteins - metabolism; Protein Interaction Maps; Protein–protein interactions; Surface expression; U251 glioblastoma cells; Yeast two-hybrid screening; β-COP; Yeast two-hybrid screening; ANO1; β-COP; Protein–protein interactions; Surface expression; U251 glioblastoma cells
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2016.05.077

Anoctamin-1 (ANO1) is a Ca2+-activated chloride channel (CaCC) that plays important physiological roles in normal and cancerous tissues. However, the plasma membrane trafficking mechanisms of ANO1 remain poorly characterized. In yeast two-hybrid screening experiments, we observed direct interactions of ANO1 with β-COP, which is a subunit of Coat Protein Complex I (COPI). This interaction was then confirmed using several in vitro and in vivo binding assays. Moreover, the cotransfection of β-COP with ANO1 into HEK293T cells led to decreased the surface expression and the channel activity of ANO1. Accordingly, endogenous ANO1 was associated with β-COP in U251 glioblastoma cells, and silencing of β-COP enhanced surface expression and whole-cell currents of ANO1 in these cells. Taken together, these data suggest that β-COP negatively regulates ANO1 surface expression.
•β-COP directly binds to the N-terminus of ANO1.•Surface expression of ANO1 is suppressed by β-COP in a heterologous system.•The overexpression of β-COP reduced endogenous ANO1 surface expression in U251 cells.•Knockdown of β-COP enhanced endogenous ANO1 surface expression in U251 cells.