scholarly journals Interactions of ubiquitin and CHMP5 with the V domain of HD-PTP reveals role for regulation of Vps4 ATPase

Author(s):  
Natalya Pashkova ◽  
Liping Yu ◽  
Nicholas J. Schnicker ◽  
Chun-Che Tseng ◽  
Lokesh Gakhar ◽  
...  

The family of Bro1 proteins coordinates the activity of the Endosomal Sorting Complexes Required for Transport (ESCRTs) to mediate a number of membrane remodeling events. These events culminate in membrane scission catalyzed by ESCRT-III, whose polymerization and disassembly is controlled by the AAA-ATPase, Vps4. Bro1-family members Alix and HD-PTP as well as yeast Bro1 have a central ‘V’ domains that non-covalently bind Ub and connect ubiquitinated proteins to ESCRT-driven functions such as the incorporation of ubiquitinated membrane proteins into intralumenal vesicles of multivesicular bodies. Recently, it was discovered that the V domain of yeast Bro1 binds the MIT domain of Vps4 to stimulate its ATPase activity. Here we determine the structural basis for how the V domain of human HD-PTP binds ubiquitin. The HD-PTP V domain also binds the MIT domain of Vps4 and ubiquitin-binding to the HD-PTP V domain enhances its ability to stimulate Vps4 ATPase activity. Additionally, we found V domains of both HD-PTP and Bro1 bind CHMP5 and Vps60, respectively, providing another potential molecular mechanism to alter Vps4 activity. These data support a model whereby contacts between ubiquitin, ESCRT-III, and Vps4 by V domains of the Bro1 family may coordinate late events in ESCRT-driven membrane remodeling events.

2021 ◽  
Vol 220 (8) ◽  
Author(s):  
Chun-Che Tseng ◽  
Shirley Dean ◽  
Brian A. Davies ◽  
Ishara F. Azmi ◽  
Natalya Pashkova ◽  
...  

Endosomal sorting complexes required for transport (ESCRT-0, -I, -II, -III) execute cargo sorting and intralumenal vesicle (ILV) formation during conversion of endosomes to multivesicular bodies (MVBs). The AAA-ATPase Vps4 regulates the ESCRT-III polymer to facilitate membrane remodeling and ILV scission during MVB biogenesis. Here, we show that the conserved V domain of ESCRT-associated protein Bro1 (the yeast homologue of mammalian proteins ALIX and HD-PTP) directly stimulates Vps4. This activity is required for MVB cargo sorting. Furthermore, the Bro1 V domain alone supports Vps4/ESCRT–driven ILV formation in vivo without efficient MVB cargo sorting. These results reveal a novel activity of the V domains of Bro1 homologues in licensing ESCRT-III–dependent ILV formation and suggest a role in coordinating cargo sorting with membrane remodeling during MVB sorting. Moreover, ubiquitin binding enhances V domain stimulation of Vps4 to promote ILV formation via the Bro1–Vps4–ESCRT-III axis, uncovering a novel role for ubiquitin during MVB biogenesis in addition to facilitating cargo recognition.


2020 ◽  
Author(s):  
Chun-che Tseng ◽  
Shirley Dean ◽  
Brian A. Davies ◽  
Ishara F. Azmi ◽  
Natalya Pashkova ◽  
...  

AbstractEndosomal sorting complexes required for transport (ESCRT-0, -I, -II, -III) form intralumenal vesicles (ILVs) during the conversion of endosomes to multivesicular bodies (MVBs). The assembly and disassembly of an ESCRT-III polymer facilitates membrane remodeling and scission during this process. The ESCRT-III-associated protein Bro1 (the yeast homolog of mammalian proteins ALIX and HD-PTP) promotes ESCRT-III assembly and inhibits disassembly of ESCRT-III filaments by impeding Vps4, a AAA-ATPase that dismantles ESCRT-III polymers. Here we show that the evolutionarily conserved “V domain” of Bro1-family proteins directly stimulate Vps4 ATPase activity and this activity is enhanced by interaction with ubiquitin. Surprisingly, a carboxyl-terminal fragment of Bro1 containing the V domain supports ILV formation but not sorting of cargo into ILVs, revealing that these two processes can be uncoupled. These studies implicate Bro1 as a factor coordinating cargo sorting with direct regulation of Vps4 to modulate ESCRT-III driven ILV formation during MVB biogenesis.


2015 ◽  
Vol 26 (7) ◽  
pp. 1345-1356 ◽  
Author(s):  
Tess Shideler ◽  
Daniel P. Nickerson ◽  
Alexey J. Merz ◽  
Greg Odorizzi

Vps9 and Muk1 are guanine nucleotide exchange factors (GEFs) in Saccharomyces cerevisiae that regulate membrane trafficking in the endolysosomal pathway by activating Rab5 GTPases. We show that Vps9 is the primary Rab5 GEF required for biogenesis of late endosomal multivesicular bodies (MVBs). However, only Vps9 (but not Muk1) is required for the formation of aberrant class E compartments that arise upon dysfunction of endosomal sorting complexes required for transport (ESCRTs). ESCRT dysfunction causes ubiquitinated transmembrane proteins to accumulate at endosomes, and we demonstrate that endosomal recruitment of Vps9 is promoted by its ubiquitin-binding CUE domain. Muk1 lacks ubiquitin-binding motifs, but its fusion to the Vps9 CUE domain allows Muk1 to rescue endosome morphology, cargo trafficking, and cellular stress-tolerance phenotypes that result from loss of Vps9 function. These results indicate that ubiquitin binding by the CUE domain promotes Vps9 function in endolysosomal membrane trafficking via promotion of localization.


2007 ◽  
Vol 179 (3) ◽  
pp. 485-500 ◽  
Author(s):  
Maria Filimonenko ◽  
Susanne Stuffers ◽  
Camilla Raiborg ◽  
Ai Yamamoto ◽  
Lene Malerød ◽  
...  

The endosomal sorting complexes required for transport (ESCRTs) are required to sort integral membrane proteins into intralumenal vesicles of the multivesicular body (MVB). Mutations in the ESCRT-III subunit CHMP2B were recently associated with frontotemporal dementia and amyotrophic lateral sclerosis (ALS), neurodegenerative diseases characterized by abnormal ubiquitin-positive protein deposits in affected neurons. We show here that autophagic degradation is inhibited in cells depleted of ESCRT subunits and in cells expressing CHMP2B mutants, leading to accumulation of protein aggregates containing ubiquitinated proteins, p62 and Alfy. Moreover, we find that functional MVBs are required for clearance of TDP-43 (identified as the major ubiquitinated protein in ALS and frontotemporal lobar degeneration with ubiquitin deposits), and of expanded polyglutamine aggregates associated with Huntington's disease. Together, our data indicate that efficient autophagic degradation requires functional MVBs and provide a possible explanation to the observed neurodegenerative phenotype seen in patients with CHMP2B mutations.


2010 ◽  
Vol 21 (6) ◽  
pp. 1023-1032 ◽  
Author(s):  
Daniel P. Nickerson ◽  
Matthew West ◽  
Ryan Henry ◽  
Greg Odorizzi

Recruitment of endosomal sorting complexes required for transport (ESCRTs) to the cytosolic face of endosomes regulates selective inclusion of transmembrane proteins into the lumenal vesicles of multivesicular bodies (MVBs). ESCRT-0, -I, and -II bind directly to ubiquitinated transmembrane cargoes of the MVB pathway, whereas polymerization of ESCRT-III at endosomes is thought to bend the membrane and/or provide the energetic force that drives membrane scission and detachment of vesicles into the endosome lumen. Disassembly of the ESCRT-III polymer and dissociation of its subunits from endosomes requires the Vps4 ATPase, the activity of which is controlled in vivo by regulatory proteins. We identify distinct spatiotemporal roles for Vps4-regulating proteins through examinations of subcellular localization and endosome morphology. Did2 plays a unique role in the regulation of MVB lumenal vesicle size, whereas Vtal and Vps60 promote efficient membrane scission and delivery of membrane to the endosome lumen. These morphological effects probably result from Vps4-mediated manipulations of ESCRT-III, because we show dissociation of ESCRT-0, -I, and -II from endosomes is not directly dependent on Vps4 activity.


2009 ◽  
Vol 37 (1) ◽  
pp. 143-145 ◽  
Author(s):  
Brian A. Davies ◽  
Ishara F. Azmi ◽  
David J. Katzmann

MVB (multivesicular body) formation occurs when the limiting membrane of an endosome invaginates into the intraluminal space and buds into the lumen, bringing with it a subset of transmembrane cargoes. Exvagination of the endosomal membrane from the cytosol is topologically similar to the budding of retroviral particles and cytokinesis, wherein membranes bud away from the cytoplasm, and the machinery responsible for MVB sorting has been implicated in these phenomena. The AAA (ATPase associated with various cellular activities) Vps4 (vacuolar protein sorting 4) performs a critical function in the MVB sorting pathway. Vps4 appears to dissociate the ESCRTs (endosomal sorting complexes required for transport) from endosomal membranes during the course of MVB sorting, but it is unclear how Vps4 ATPase activity is synchronized with ESCRT release. We have investigated the mechanisms by which ESCRT components stimulate the ATPase activity of Vps4. These studies support a model wherein Vps4 activity is subject to spatial and temporal regulation via distinct mechanisms during MVB sorting.


2009 ◽  
Vol 185 (2) ◽  
pp. 213-224 ◽  
Author(s):  
S. Brookhart Shields ◽  
Andrea J. Oestreich ◽  
Stanley Winistorfer ◽  
Doris Nguyen ◽  
Johanna A. Payne ◽  
...  

Ubiquitin (Ub) sorting receptors facilitate the targeting of ubiquitinated membrane proteins into multivesicular bodies (MVBs). Ub-binding domains (UBDs) have been described in several endosomal sorting complexes required for transport (ESCRT). Using available structural information, we have investigated the role of the multiple UBDs within ESCRTs during MVB cargo selection. We found a novel UBD within ESCRT-I and show that it contributes to MVB sorting in concert with the known UBDs within the ESCRT complexes. These experiments reveal an unexpected level of coordination among the ESCRT UBDs, suggesting that they collectively recognize a diverse set of cargo rather than act sequentially at discrete steps.


2006 ◽  
Vol 26 (3) ◽  
pp. 822-830 ◽  
Author(s):  
James E. Mullally ◽  
Tatiana Chernova ◽  
Keith D. Wilkinson

ABSTRACT Cdc48 (p97/VCP) is an AAA-ATPase molecular chaperone whose cellular functions are facilitated by its interaction with ubiquitin binding cofactors (e.g., Npl4-Ufd1 and Shp1). Several studies have shown that Saccharomyces cerevisiae Doa1 (Ufd3/Zzz4) and its mammalian homologue, PLAA, interact with Cdc48. However, the function of this interaction has not been determined, nor has a physiological link between these proteins been demonstrated. Herein, we demonstrate that Cdc48 interacts directly with the C-terminal PUL domain of Doa1. We find that Doa1 possesses a novel ubiquitin binding domain (we propose the name PFU domain, for PLAA family ubiquitin binding domain), which appears to be necessary for Doa1 function. Our data suggest that the PUL and PFU domains of Doa1 promote the formation of a Doa1-Cdc48-ubiquitin ternary complex, potentially allowing for the recruitment of ubiquitinated proteins to Cdc48. DOA1 and CDC48 mutations are epistatic, suggesting that their interaction is physiologically relevant. Lastly, we provide evidence of functional conservation within the PLAA family by showing that a human-yeast chimera binds to ubiquitin and complements doa1Δ phenotypes in yeast. Combined, our data suggest that Doa1 plays a physiological role as a ubiquitin binding cofactor of Cdc48 and that human PLAA may play an analogous role via its interaction with p97/VCP.


2018 ◽  
Vol 34 (1) ◽  
pp. 85-109 ◽  
Author(s):  
John McCullough ◽  
Adam Frost ◽  
Wesley I. Sundquist

The endosomal sorting complexes required for transport (ESCRT) pathway mediates cellular membrane remodeling and fission reactions. The pathway comprises five core complexes: ALIX, ESCRT-I, ESCRT-II, ESCRT-III, and Vps4. These soluble complexes are typically recruited to target membranes by site-specific adaptors that bind one or both of the early-acting ESCRT factors: ALIX and ESCRT-I/ESCRT-II. These factors, in turn, nucleate assembly of ESCRT-III subunits into membrane-bound filaments that recruit the AAA ATPase Vps4. Together, ESCRT-III filaments and Vps4 remodel and sever membranes. Here, we review recent advances in our understanding of the structures, activities, and mechanisms of the ESCRT-III and Vps4 machinery, including the first high-resolution structures of ESCRT-III filaments, the assembled Vps4 enzyme in complex with an ESCRT-III substrate, the discovery that ESCRT-III/Vps4 complexes can promote both inside-out and outside-in membrane fission reactions, and emerging mechanistic models for ESCRT-mediated membrane fission.


2014 ◽  
Vol 205 (1) ◽  
pp. 33-49 ◽  
Author(s):  
Manuel Alonso Y Adell ◽  
Georg F. Vogel ◽  
Mehrshad Pakdel ◽  
Martin Müller ◽  
Herbert Lindner ◽  
...  

Five endosomal sorting complexes required for transport (ESCRTs) mediate the degradation of ubiquitinated membrane proteins via multivesicular bodies (MVBs) in lysosomes. ESCRT-0, -I, and –II interact with cargo on endosomes. ESCRT-II also initiates the assembly of a ringlike ESCRT-III filament consisting of Vps20, Snf7, Vps24, and Vps2. The AAA–adenosine triphosphatase Vps4 disassembles and recycles the ESCRT-III complex, thereby terminating the ESCRT pathway. A mechanistic role for Vps4 in intraluminal vesicle (ILV) formation has been unclear. By combining yeast genetics, biochemistry, and electron tomography, we find that ESCRT-III assembly on endosomes is required to induce or stabilize the necks of growing MVB ILVs. Yet, ESCRT-III alone is not sufficient to complete ILV biogenesis. Rather, binding of Vps4 to ESCRT-III, coordinated by interactions with Vps2 and Snf7, is coupled to membrane neck constriction during ILV formation. Thus, Vps4 not only recycles ESCRT-III subunits but also cooperates with ESCRT-III to drive distinct membrane-remodeling steps, which lead to efficient membrane scission at the end of ILV biogenesis in vivo.


Sign in / Sign up

Export Citation Format

Share Document