VPS35 Downregulation Alters Degradation Pathways in Neuronal Cells

2021 ◽  
pp. 1-11
Author(s):  
Alessia Filippone ◽  
Jian-Guo Li ◽  
Domenico Praticò
Keyword(s):  
Complex System ◽  
Genetic Manipulation ◽  
Protein Sorting ◽  
Neuronal Cell ◽  
Integral Function ◽  
Degradation Pathways ◽  
Intracellular Degradation ◽  
Parkinson’S Diseases ◽  
Main Component ◽  
Vacuolar Protein

Background: The vacuolar protein sorting 35 (VPS35) is the main component of the retromer recognition core complex system which regulates intracellular cargo protein sorting and trafficking. Downregulation of VPS35 has been linked to the pathogenesis of neurodegenerative disorders such Alzheimer’s and Parkinson’s diseases via endosome dysregulation. Objective: Here we show that the genetic manipulation of VPS35 affects intracellular degradation pathways. Methods: A neuronal cell line expressing human APP Swedish mutant was used. VPS35 silencing was performed treating cells with VPS35 siRNA or Ctr siRNA for 72 h. Results: Downregulation of VPS35 was associated with alteration of autophagy flux and intracellular accumulation of acidic and ubiquitinated aggregates suggesting that dysfunction of the retromer recognition core leads to a significant alteration in both pathways. Conclusion: Taken together, our data demonstrate that besides cargo sorting and trafficking, VPS35 by supporting the integral function of the retromer complex system plays an important role also as a critical regulator of intracellular degradation pathways.

scholarly journals An Interorganellar Bidding War: Vps13 Localization by Competitive Organelle-Specific Adaptors

Contact ◽  
2018 ◽  
Vol 1 ◽  
pp. 251525641881462
Author(s):  
Samantha K. Dziurdzik ◽  
Björn D.M. Bean ◽  
Elizabeth Conibear
Keyword(s):  
Endoplasmic Reticulum ◽  
Recent Work ◽  
Protein Sorting ◽  
Repeat Region ◽  
Vacuolar Protein Sorting ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Prospore Membrane ◽  
Membrane Contact ◽  
Vacuolar Protein

Membrane contact sites are regulated through the controlled recruitment of constituent proteins. Yeast vacuolar protein sorting 13 (Vps13) dynamically localizes to membrane contact sites at endosomes, vacuoles, mitochondria, and the endoplasmic reticulum under different cellular conditions and is recruited to the prospore membrane during meiosis. Prior to our recent work, the mechanism for localization at contact sites was largely unknown. We identified Ypt35 as a novel Vps13 adaptor for endosomes and the nucleus-vacuole junction. Furthermore, we discovered a conserved recruitment motif in Ypt35 and found related motifs in the prospore membrane and mitochondrial adaptors, Spo71 and Mcp1, respectively. All three adaptors compete for binding to a six-repeat region of Vps13, suggesting adaptor competition regulates Vps13 localization. Here, we summarize and discuss the implications of our work, highlighting key outstanding questions.

MP005INCREASED LYSOSOMAL DEGRADATION OF AQP2 IN MPKCCDC14 CELLS WITH KNOCKDOWN OF VACUOLAR PROTEIN SORTING-ASSOCIATED PROTEIN 35

2016 ◽  
Vol 31 (suppl_1) ◽  
pp. i345-i345
Author(s):  
Hyo-Jung Choi ◽  
Mi Suk Lee ◽  
Dasom Kim ◽  
Eui-Jung Park ◽  
Yu-Jung Lee ◽  
...  
Keyword(s):  
Protein Sorting ◽  
Lysosomal Degradation ◽  
Vacuolar Protein Sorting ◽  
Vacuolar Protein

scholarly journals The HOPS complex mediates autophagosome–lysosome fusion through interaction with syntaxin 17

2014 ◽  
Vol 25 (8) ◽  
pp. 1327-1337 ◽  
Author(s):  
Peidu Jiang ◽  
Taki Nishimura ◽  
Yuriko Sakamaki ◽  
Eisuke Itakura ◽  
Tomohisa Hatta ◽  
...  
Keyword(s):  
Protein Sorting ◽  
Endocytic Pathway ◽  
Mass Spectrometry Analysis ◽  
Autophagic Flux ◽  
Interacting Protein ◽  
Spectrometry Analysis ◽  
Sensitive Factor ◽  
Protein Receptors ◽  
Vacuolar Protein ◽  
Hops Complex

Membrane fusion is generally controlled by Rabs, soluble N-ethylmaleimide–sensitive factor attachment protein receptors (SNAREs), and tethering complexes. Syntaxin 17 (STX17) was recently identified as the autophagosomal SNARE required for autophagosome–lysosome fusion in mammals and Drosophila. In this study, to better understand the mechanism of autophagosome–lysosome fusion, we searched for STX17-interacting proteins. Immunoprecipitation and mass spectrometry analysis identified vacuolar protein sorting 33A (VPS33A) and VPS16, which are components of the homotypic fusion and protein sorting (HOPS)–tethering complex. We further confirmed that all HOPS components were coprecipitated with STX17. Knockdown of VPS33A, VPS16, or VPS39 blocked autophagic flux and caused accumulation of STX17- and microtubule-associated protein light chain (LC3)–positive autophagosomes. The endocytic pathway was also affected by knockdown of VPS33A, as previously reported, but not by knockdown of STX17. By contrast, ultraviolet irradiation resistance–associated gene (UVRAG), a known HOPS-interacting protein, did not interact with the STX17–HOPS complex and may not be directly involved in autophagosome–lysosome fusion. Collectively these results suggest that, in addition to its well-established function in the endocytic pathway, HOPS promotes autophagosome–lysosome fusion through interaction with STX17.

Recruitment of the endosomal WASH complex is mediated by the extended ‘tail’ of Fam21 binding to the retromer protein Vps35

2012 ◽  
Vol 442 (1) ◽  
pp. 209-220 ◽  
Author(s):  
Michael E. Harbour ◽  
Sophia Y. Breusegem ◽  
Matthew N. J. Seaman
Keyword(s):  
Membrane Proteins ◽  
Protein Sorting ◽  
Complex Interaction ◽  
Membrane Association ◽  
Tail Domain ◽  
Fk506 Binding Protein ◽  
Retromer Complex ◽  
Multimeric Protein ◽  
Vacuolar Protein ◽  
Necessary And Sufficient

The retromer complex is a conserved endosomal protein sorting complex that sorts membrane proteins into nascent endosomal tubules. The recognition of membrane proteins is mediated by the cargo-selective retromer complex, a stable trimer of the Vps35 (vacuolar protein sorting 35), Vps29 and Vps26 proteins. We have recently reported that the cargo-selective retromer complex associates with the WASH (Wiskott–Aldrich syndrome homologue) complex, a multimeric protein complex that regulates tubule dynamics at endosomes. In the present study, we show that the retromer–WASH complex interaction occurs through the long unstructured ‘tail’ domain of the WASH complex–Fam21 protein binding to Vps35, an interaction that is necessary and sufficient to target the WASH complex to endosomes. The Fam21-tail also binds to FKBP15 (FK506-binding protein 15), a protein associated with ulcerative colitis, to mediate the membrane association of FKBP15. Elevated Fam21-tail expression inhibits the association of the WASH complex with retromer, resulting in increased cytoplasmic WASH complex. Additionally, overexpression of the Fam21-tail results in cell-spreading defects, implicating the activity of the WASH complex in regulating the mobilization of membrane into the endosome-to-cell surface pathway.

Vacuolar Protein Sorting in Yeast

1993 ◽  
pp. 329-338
Author(s):  
Bruce F. Horazdovsky ◽  
Todd R. Graham ◽  
Scott D. Emr
Keyword(s):  
Protein Sorting ◽  
Vacuolar Protein Sorting ◽  
Vacuolar Protein
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