RRC ID 47487
Author Hirano T, Katoh Y, Nakayama K.
Title Intraflagellar transport-A complex mediates ciliary entry and retrograde trafficking of ciliary G protein-coupled receptors.
Journal Mol Biol Cell
Abstract Cilia serve as cellular antennae where proteins involved in sensory and developmental signaling, including G protein-coupled receptors (GPCRs), are specifically localized. Intraflagellar transport (IFT)-A and -B complexes mediate retrograde and anterograde ciliary protein trafficking, respectively. Using a visible immunoprecipitation assay to detect protein-protein interactions, we show that the IFT-A complex is divided into a core subcomplex, composed of IFT122/IFT140/IFT144, which is associated with TULP3, and a peripheral subcomplex, composed of IFT43/IFT121/IFT139, where IFT139 is most distally located. IFT139-knockout (KO) and IFT144-KO cells demonstrated distinct phenotypes: IFT139-KO cells showed the accumulation of IFT-A, IFT-B, and GPCRs, including Smoothened and GPR161, at the bulged ciliary tips; IFT144-KO cells showed failed ciliary entry of IFT-A and GPCRs and IFT-B accumulation at the bulged tips. These observations demonstrate the distinct roles of the core and peripheral IFT-A subunits: IFT139 is dispensable for IFT-A assembly but essential for retrograde trafficking of IFT-A, IFT-B, and GPCRs; in contrast, IFT144 is essential for functional IFT-A assembly and ciliary entry of GPCRs but dispensable for anterograde IFT-B trafficking. Thus the data presented here demonstrate that the IFT-A complex mediates not only retrograde trafficking but also entry into cilia of GPCRs.
Volume 28(3)
Pages 429-439
Published 2017-2-1
DOI 10.1091/mbc.E16-11-0813
PII mbc.E16-11-0813
PMID 27932497
PMC PMC5341726
MeSH Animals Biological Transport Carrier Proteins / metabolism Cell Line Cell Movement Cilia / genetics* Cilia / metabolism* Cilia / physiology Flagella / metabolism* Humans Protein Transport Receptors, G-Protein-Coupled / metabolism Signal Transduction
IF 3.791
Times Cited 38
DNA material Genome Network Project Human cDNA Clone IRAL009C12 (HGY083660) IRAK069L05 (HGX027869) IRAK069G14 (HGX027758) pCAG2-EGFP-C1-IFT122 (RDB15190) pCAG2-mCherry-C1-IFT122 (RDB15191) pCAG2-EGFP-C1-IFT140 (RDB15192) pCAG2-mCherry-C1-IFT140 (RDB15193) pEGFP-C1-TULP3 (RDB15194) pmCherry-C1-TULP3 (RDB15195).