title: Identification of the topology and functional domains of PAQR10.
abstract: PAQR10 (progestin and adipoQ receptor 10) is a Golgi-localized protein that is able to enhance the retention and activation of Ras proteins in the Golgi apparatus, subsequently leading to a sustained ERK (extracellular-signal-regulated kinase) signalling. However, little is known about the topology and functional domains of PAQR10. In the present study, we extensively dissected and analysed the structure of PAQR10. The topology analysis reveals that PAQR10 is an integral membrane protein with its N-terminus facing the cytosol. Multiple domains, including the membrane-proximal region at the N-terminus, the membrane-proximal region at the C-terminus and the three loops facing the cytosol, were found to be required for PAQR10 to reside in the Golgi apparatus, to stimulate ERK phosphorylation and to tether Ras to the Golgi apparatus. Furthermore, when PAQR10 was artificially forced to be expressed in the endoplasmic reticulum, it could neither mobilize Ras to the Golgi apparatus nor increase ERK phosphorylation. Finally, the PAQR10 mutants that lost Golgi localization failed to promote differentiation of PC12 cells. Collectively, the results of the present study indicate that Golgi localization is indispensable for PAQR10 to implement its regulatory functions in the Ras signalling cascade.
authors.affiliation: Key Laboratory of Nutrition and Metabolism, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, 294 Taiyuan Road, Shanghai 200031, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Jin
authors.forename: Daqian
authors.initials: D
authors.lastname: Xu
authors.forename: Qiurong
authors.initials: Q
authors.lastname: Ding
authors.forename: Yixuan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Chenqian
authors.initials: C
authors.lastname: Mao
authors.forename: Yi
authors.initials: Y
authors.lastname: Pan
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002454:Cell Differentiation; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D016716:PC12 Cells; D010766:Phosphorylation; D011487:Protein Conformation; D051381:Rats; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology
chemical_list: C572580:MMD2 protein, human; D011956:Receptors, Cell Surface