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Kustigian L, Gong X, Gai W, Thongchol J, Zhang J, Puchalla J, Carr CM, Rye HS. GTP-stimulated membrane fission by the N-BAR protein AMPH-1. Traffic 2023; 24:34-47. [PMID: 36435193 PMCID: PMC9825645 DOI: 10.1111/tra.12875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 10/24/2022] [Accepted: 11/19/2022] [Indexed: 11/28/2022]
Abstract
Membrane-enclosed transport carriers sort biological molecules between stations in the cell in a dynamic process that is fundamental to the physiology of eukaryotic organisms. While much is known about the formation and release of carriers from specific intracellular membranes, the mechanism of carrier formation from the recycling endosome, a compartment central to cellular signaling, remains to be resolved. In Caenorhabditis elegans, formation of transport carriers from the recycling endosome requires the dynamin-like, Eps15-homology domain (EHD) protein, RME-1, functioning with the Bin/Amphiphysin/Rvs (N-BAR) domain protein, AMPH-1. Here we show, using a free-solution single-particle technique known as burst analysis spectroscopy (BAS), that AMPH-1 alone creates small, tubular-vesicular products from large, unilamellar vesicles by membrane fission. Membrane fission requires the amphipathic H0 helix of AMPH-1 and is slowed in the presence of RME-1. Unexpectedly, AMPH-1-induced membrane fission is stimulated in the presence of GTP. Furthermore, the GTP-stimulated membrane fission activity seen for AMPH-1 is recapitulated by the heterodimeric N-BAR amphiphysin protein from yeast, Rvs161/167p, strongly suggesting that GTP-stimulated membrane fission is a general property of this important class of N-BAR proteins.
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Affiliation(s)
- Lauren Kustigian
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77845, USA
- Current address: GlaxoSmithKline, 1250 South Collegeville Rd., Collegeville, Pennsylvania 19426, USA
| | - Xue Gong
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77845, USA
| | - Wei Gai
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77845, USA
| | - Jirapat Thongchol
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77845, USA
| | - Junjie Zhang
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77845, USA
| | - Jason Puchalla
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - Chavela M. Carr
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77845, USA
| | - Hays S. Rye
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas, 77845, USA
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Shoup D, Roth A, Puchalla J, Rye HS. The Impact of Hidden Structure on Aggregate Disassembly by Molecular Chaperones. Front Mol Biosci 2022; 9:915307. [PMID: 35874607 PMCID: PMC9302491 DOI: 10.3389/fmolb.2022.915307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Protein aggregation, or the uncontrolled self-assembly of partially folded proteins, is an ever-present danger for living organisms. Unimpeded, protein aggregation can result in severe cellular dysfunction and disease. A group of proteins known as molecular chaperones is responsible for dismantling protein aggregates. However, how protein aggregates are recognized and disassembled remains poorly understood. Here we employ a single particle fluorescence technique known as Burst Analysis Spectroscopy (BAS), in combination with two structurally distinct aggregate types grown from the same starting protein, to examine the mechanism of chaperone-mediated protein disaggregation. Using the core bi-chaperone disaggregase system from Escherichia coli as a model, we demonstrate that, in contrast to prevailing models, the overall size of an aggregate particle has, at most, a minor influence on the progression of aggregate disassembly. Rather, we show that changes in internal structure, which have no observable impact on aggregate particle size or molecular chaperone binding, can dramatically limit the ability of the bi-chaperone system to take aggregates apart. In addition, these structural alterations progress with surprising speed, rendering aggregates resistant to disassembly within minutes. Thus, while protein aggregate structure is generally poorly defined and is often obscured by heterogeneous and complex particle distributions, it can have a determinative impact on the ability of cellular quality control systems to process protein aggregates.
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Affiliation(s)
- Daniel Shoup
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Andrew Roth
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
| | - Jason Puchalla
- Department of Physics, Princeton University, Princeton, NJ, United States
| | - Hays S. Rye
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
- *Correspondence: Hays S. Rye,
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