Mechanism and cellular function of direct membrane binding by the ESCRT and ERES-associated Ca 2+ -sensor ALG-2.

Autor:	Shukla S; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA., Chen W; Department of Biological Chemistry, University of Michigan School of Medicine, 1150 W. Medical Center Drive, Ann Arbor, MI, 48109, USA., Rao S; Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany., Yang S; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA., Ou C; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA., Larsen KP; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA., Hummer G; Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.; Institute of Biophysics, Goethe University Frankfurt, Frankfurt am Main 60438, Germany., Hanson PI; Department of Biological Chemistry, University of Michigan School of Medicine, 1150 W. Medical Center Drive, Ann Arbor, MI, 48109, USA., Hurley JH; Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA.
Jazyk:	angličtina
Zdroj:	BioRxiv : the preprint server for biology [bioRxiv] 2023 Oct 19. Date of Electronic Publication: 2023 Oct 19.
DOI:	10.1101/2023.10.17.562764
Abstrakt:	Apoptosis Linked Gene-2 (ALG-2) is a multifunctional intracellular Ca 2+ sensor and the archetypal member of the penta-EF hand protein family. ALG-2 functions in the repair of damage to both the plasma and lysosome membranes and in COPII-dependent budding at endoplasmic reticulum exit sites (ERES). In the presence of Ca 2+ , ALG-2 binds to ESCRT-I and ALIX in membrane repair and to SEC31A at ERES. ALG-2 also binds directly to acidic membranes in the presence of Ca 2+ by a combination of electrostatic and hydrophobic interactions. By combining GUV-based experiments and molecular dynamics simulations, we show that charge-reversed mutants of ALG-2 at these locations disrupt membrane recruitment. ALG-2 membrane binding mutants have reduced or abrogated ERES localization in response to Thapsigargin-induced Ca 2+ release but still localize to lysosomes following lysosomal Ca 2+ release. In vitro reconstitution shows that the ALG-2 membrane-binding defect can be rescued by binding to ESCRT-I. These data thus reveal the nature of direct Ca 2+ -dependent membrane binding and its interplay with Ca 2+ -dependent protein binding in the cellular functions of ALG-2. Competing Interests: Competing interests: J.H.H. is a co-founder and shareholder of Casma Therapeutics and receives research funding from Genentech and Hoffmann-La Roche.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu