RRC ID 45515
Author Homma Y, Fukuda M.
Title Rabin8 regulates neurite outgrowth in both GEF activity-dependent and -independent manners.
Journal Mol Biol Cell
Abstract Many aspects of membrane-trafficking events are regulated by Rab-family small GTPases. Neurite outgrowth requires massive addition of proteins and lipids to the tips of growing neurites by membrane trafficking, and although several Rabs, including Rab8, Rab10, and Rab11, have been implicated in this process, their regulatory mechanisms during neurite outgrowth are poorly understood. Here, we show that Rabin8, a Rab8-guanine nucleotide exchange factor (GEF), regulates nerve growth factor (NGF)-induced neurite outgrowth of PC12 cells. Knockdown of Rabin8 results in inhibition of neurite outgrowth, whereas overexpression promotes it. We also find that Rab10 is a novel substrate of Rabin8 and that both Rab8 and Rab10 function during neurite outgrowth downstream of Rabin8. Surprisingly, however, a GEF activity-deficient isoform of Rabin8 also promotes neurite outgrowth, indicating the existence of a GEF activity-independent role of Rabin8. The Arf6/Rab8-positive recycling endosomes (Arf6/Rab8-REs) and Rab10/Rab11-positive REs (Rab10/Rab11-REs) in NGF-stimulated PC12 cells are differently distributed. Rabin8 localizes on both RE populations and appears to activate Rab8 and Rab10 there. These localizations and functions of Rabin8 are Rab11 dependent. Thus Rabin8 regulates neurite outgrowth both by coordinating with Rab8, Rab10, and Rab11 and by a GEF activity-independent mechanism.
Volume 27(13)
Pages 2107-18
Published 2016-7-1
DOI 10.1091/mbc.E16-02-0091
PII mbc.E16-02-0091
PMID 27170183
PMC PMC4927283
MeSH Animals DNA-Binding Proteins / genetics DNA-Binding Proteins / metabolism Endosomes / metabolism Germinal Center Kinases Guanine Nucleotide Exchange Factors / metabolism Neurites / metabolism Neuronal Outgrowth PC12 Cells Protein Serine-Threonine Kinases / genetics* Protein Serine-Threonine Kinases / metabolism* Protein Transport Rats Transcription Factors / genetics Transcription Factors / metabolism rab GTP-Binding Proteins / metabolism
IF 3.791
Times Cited 30
DNA material pEF-FLAG-mouse Rab8A (RDB14271) pEF-FLAG-mouse Rab10 (RDB14272) pEGFP-C1-mouse Rab8A (RDB14273) pEGFP-C1-mouse Rab10 (RDB14274) pEGFPC1-mouse Rab8A-Q67L - constitutive active (RDB14275) pEGFPC1-mouse Rab8A-T22N - constitutive negative (RDB14276) pEGFPC1-mouse Rab10-Q68L - constitutive active (RDB14277) pEGFPC1-mouse Rab10-T23N - constitutive negative (RDB14278) pEGFP-C1-mouse Rabin8-delGEF-300-305 - GEF-activity/Rab11-binding-deficient (RDB14279) pEGFP-C1-mouse Rabin8-delGEF - GEF-activity-deficient (RDB14280) pEGFP-C1-mouse Rabin8-SR-del300-305 - SR siRNA-resistant (RDB14281) pEGFP-C1-mouse Rabin8-SR - SR siRNA-resistant (RDB14282) pEGFP-C1-mouse Rabin8 (RDB14283) pSilencer-rat Rabin8-st2 (RDB14284) pGEX4T3-mouse MICAL-L2-C - active Rab8/10 trapper (RDB14285) pEGFP-C1-Rab40 (RDB14338).