Silencing of OSBP-related protein 8 (ORP8) modifies the macrophage transcriptome, nucleoporin p62 distribution, and migration capacity
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- 作者：Olivier B¨¦aslas ; Terhi Vihervaara ; Jiwei Li ; Pirkka-Pekka Laurila ; Daoguang Yan ; Vesa M. Olkkonen
- 关键词：ABCA1 ; ATP-binding cassette transporter A1 ; ER ; Endoplasmic reticulum ; Exo70 ; Exocyst complex protein of 70 ; kDa ; GST ; Glutathione-S-transferase ; NPC ; Nuclear Pore Complex ; NUP62 ; Nucleoporin p62 ; ORP ; OSBP-related protein ; OSBP ; Oxysterol-binding pro
- 刊名：Experimental Cell Research
- 出版年：2012
- 出版时间：10 September, 2012
- 年：2012
- 卷：318
- 期：15
- 页码：1933-1945
- 全文大小：1285 K
文摘
ORP8 is an oxysterol/cholesterol binding protein anchored to the endoplasmic reticulum and the nuclear envelope, and is abundantly expressed in the macrophage. We created and characterized mouse RAW264.7 macrophages with ORP8 stably silenced using shRNA lentiviruses. A microarray transcriptome and gene ontology pathway analysis revealed significant alterations in several nuclear pathways and ones associated with centrosome and microtubule organization. ORP8 knockdown resulted in increased expression and altered subcellular distribution of an interaction partner of ORP8, nucleoporin NUP62, with an intranuclear localization aspect and association with cytoplasmic vesicular structures and lamellipodial edges of the cells. Moreover, ORP8 silenced cells displayed enhanced migration, and a more pronounced microtubule cytoskeleton than controls expressing a non-targeting shRNA. ORP8 was shown to compete with Exo70 for interaction with NUP62, and NUP62 knockdown abolished the migration enhancement of ORP8-silenced cells, suggesting that the endogenous ORP8 suppresses migration via binding to NUP62. As a conclusion, the present study reveals new, unexpected aspects of ORP8 function in macrophages not directly involving lipid metabolism, but rather associated with nuclear functions, microtubule organization, and migration capacity.