The Arf4-rhodopsin complex (mediated by the VxPx motif in rhodopsin) initiates expansion of vertebrate rod photoreceptor cilia-derived light-sensing organelles through stepwise assembly of a conserved trafficking network. Here, we examine its role in the sorting of VAMP7 (also known as TI-VAMP) - an R-SNARE possessing a regulatory longin domain (LD) - into rhodopsin transport carriers (RTCs). During RTC formation and trafficking, VAMP7 colocalizes with the ciliary cargo rhodopsin and interacts with the Rab11-Rabin8-Rab8 trafficking module. Rab11 and Rab8 bind the VAMP7 LD, whereas Rabin8 (also known as RAB3IP) interacts with the SNARE domain. The Arf/Rab11 effector FIP3 (also known as RAB11FIP3) regulates VAMP7 access to Rab11. At the ciliary base, VAMP7 forms a complex with the cognate SNAREs syntaxin 3 and SNAP-25. When expressed in transgenic animals, a GFP-VAMP7ΔLD fusion protein and a Y45E phosphomimetic mutant colocalize with endogenous VAMP7. The GFP-VAMP7-R150E mutant displays considerable localization defects that imply an important role of the R-SNARE motif in intracellular trafficking, rather than cognate SNARE pairing. Our study defines the link between VAMP7 and the ciliary targeting nexus that is conserved across diverse cell types, and contributes to general understanding of how functional Arf and Rab networks assemble SNAREs in membrane trafficking.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6307879 | PMC |
| http://dx.doi.org/10.1242/jcs.222034 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Electron Tomography of Organelles and Vesicles in the Investigation of SNARE Function and Localization.
Methods Mol Biol
January 2025
Cambridge Institute for Medical Research (CIMR) and Department of Clinical Biochemistry, University of Cambridge School of Clinical Medicine, Cambridge, UK.
Electron tomography can provide additional morphological information not easily obtained by conventional transmission electron microscopy of thin sections. It uses a goniometer stage in the electron microscope to tilt the specimen and collect a series of 2D images from different orientations, which are combined to provide a 3D volume tomogram and a colored reconstruction of the morphological feature(s) of interest. Here we describe the protocols for its use in visualizing changes in organelle morphology after depletion of the SNARE proteins VAMP7 and VAMP8 and to study VAMP7 localization on endolysosomes/lysosomes.
View Article and Find Full Text PDFRabin8 phosphorylated by NDR2/STK38L, the canine early retinal degeneration (erd) gene product, directs rhodopsin Golgi-to-cilia trafficking.
J Cell Sci
January 2025
Department of Ophthalmology and Visual Sciences, University of New Mexico, Albuquerque, New Mexico 87131, Mexico.
The Rab11-Rabin8-Rab8 ciliogenesis complex regulates the expansion of cilia-derived light-sensing organelles, the rod outer segments, via post-Golgi rhodopsin transport carriers (RTCs). Rabin8, an effector of Rab11 and a nucleotide exchange factor (GEF) for Rab8, is phosphorylated at S272 by NDR2 kinase (aka STK38L), a canine erd gene product linked to the human ciliopathy Leber congenital amaurosis (LCA). Here, we define the step at which NDR2 phosphorylated Rabin8 regulates Rab11-Rab8 succession in X.
View Article and Find Full Text PDFDevelopment and application of a cGPS 20K liquid-phase SNP microarray in Jiaji ducks.
Poult Sci
December 2024
Institute of Animal Science and Veterinary Medicine, Hainan Academy of Agricultural Sciences, Hainan, Haikou 571101, PR China. Electronic address:
In order to provide a low-cost, high efficient, and highly accurate tool for molecular breeding of Jiaji ducks, we constructed a cGPS(Genotyping by Pinpoint Sequencing of captured targets) 20 K liquid-phase microarray using resequencing data from this valuable poultry breed for the first time. The microarray contains 20,327 high-quality snp loci, mainly from the 30 Jiaji duck resequencing samples collected in this study, and some loci were supplemented from the 135 duck resequencing data from KUNMING INSTITUTE OF ZOOLOGY.CAS.
View Article and Find Full Text PDFQuantification of lysosomal labile Zn and monitoring of Zn efflux using a small-molecule-protein hybrid fluorescent probe.
J Inorg Biochem
March 2025
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan; Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan; Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki Aza-Aoba, Aoba-ku, Sendai, Miyagi 980-8578, Japan. Electronic address:
Lysosomal labile Zn levels have been unclear. By targeting a small-molecule fluorescent Zn probe, ZnDA-3H, to lysosomes via VAMP7-Halo, the lysosomal labile Zn concentration was determined to be 1.9 nM in HeLa cells.
View Article and Find Full Text PDFLysosomal activity depends on TRPML1-mediated Ca release coupled to incoming vesicle fusions.
J Biol Chem
December 2024
Institute of Genetics, MTA Lendület Lysosomal Degradation Research Group, HUN-REN BRC Szeged, Szeged, Hungary; Department of Anatomy, Cell and Developmental Biology, ELTE, Budapest, Hungary. Electronic address:
The lysosomal cation channel TRPML1/MCOLN1 facilitates autophagic degradation during amino acid starvation based on studies involving long-term TRMPL1 modulation. Here we show that lysosomal activation (more acidic pH and higher hydrolase activity) depends on incoming vesicle fusions. We identify an immediate, calcium-dependent role of TRPML1 in lysosomal activation through promoting autophagosome-lysosome fusions and lysosome acidification within 10 to 20 min of its pharmacological activation.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!