Search

Your search keyword '"Mdm12"' showing total 2 results
Start Over Descriptor "Mdm12" Topic biological transport
2 results on '"Mdm12"'

1. Determining the Lipid-Binding Specificity of SMP Domains: An ERMES Subunit as a Case Study

Author

AhYoung, Andrew P and Egea, Pascal F

Subjects
1.1 Normal biological development and functioning, Underpinning research, Generic health relevance, Bacteria, Biological Transport, Carrier Proteins, Chromatography, Liquid, Chromatography, Thin Layer, Endoplasmic Reticulum, Gene Expression Regulation, Liposomes, Mitochondrial Proteins, Phospholipids, Protein Interaction Domains and Motifs, Protein Subunits, Recombinant Proteins, Structure-Activity Relationship, Yeasts, ERMES, Mdm12, SMP domain, Lipid-transfer protein, Phospholipid, Membrane contact sites, Liposome, HPTLC, Lipid displacement, Liposome flotation, Other Chemical Sciences, Biochemistry and Cell Biology, Developmental Biology
Abstract

Membrane contact sites between the endoplasmic reticulum (ER) and mitochondria function as a central hub for the exchange of phospholipids and calcium. The yeast Endoplasmic Reticulum-Mitochondrion Encounter Structure (ERMES) complex is composed of five subunits that tether the ER and mitochondria. Three ERMES subunits (i.e., Mdm12, Mmm1, and Mdm34) contain the synaptotagmin-like mitochondrial lipid-binding protein (SMP) domain. The SMP domain belongs to the tubular lipid-binding protein (TULIP) superfamily, which consists of ubiquitous lipid scavenging and transfer proteins. Herein, we describe the methods for expression and purification of recombinant Mdm12, a bona fide SMP-containing protein, together with the subsequent identification of its bound phospholipids by high-performance thin-layer chromatography (HPTLC) and the characterization of its lipid exchange and transfer functions using lipid displacement and liposome flotation in vitro assays with liposomes as model biological membranes. These methods can be applied to the study and characterization of novel lipid-binding and lipid-transfer proteins.

Published
2019

2. Gem1 and<scp>ERMES</scp>Do Not Directly Affect Phosphatidylserine Transport from<scp>ER</scp>to Mitochondria or Mitochondrial Inheritance

Author

Dennis R. Voelker, Agnieszka Lewandowska, Tom A. Rapoport, Mesut Bilgin, Daniel F. Markgraf, Christer S. Ejsing, Janet M. Shaw, Mirco Junker, Tammy T. Nguyen, and Jae-Yeon Choi

Subjects
mitochondrial phospholipids, genetic structures, Cell division, Mitochondrion, Endoplasmic Reticulum, Biochemistry, Mass Spectrometry, GTP Phosphohydrolases, chemistry.chemical_compound, 0302 clinical medicine, Mdm34, Structural Biology, Mmm1, 0303 health sciences, Gem1 GTPase, Mitochondria, Cell biology, Mitochondrial DNA, Saccharomyces cerevisiae Proteins, Green Fluorescent Proteins, ERMES complex, Phosphatidylserines, Saccharomyces cerevisiae, Biology, DNA, Mitochondrial, Models, Biological, Mitochondrial Proteins, 03 medical and health sciences, ERMES, stomatognathic system, Mdm12, Mdm10, Genetics, membrane contact site (MCS), Molecular Biology, Actin, 030304 developmental biology, Phosphatidylethanolamine, Phosphatidylethanolamines, Endoplasmic reticulum, yeast Miro, Biological Transport, Original Articles, Cell Biology, biochemical phenomena, metabolism, and nutrition, Microscopy, Fluorescence, chemistry, rab GTP-Binding Proteins, ER-mitochondria, Mutation, mitochondrial movement and inheritance, 030217 neurology & neurosurgery
Abstract

In yeast, a protein complex termed the ER-Mitochondria Encounter Structure (ERMES) tethers mitochondria to the endoplasmic reticulum. ERMES proteins are implicated in a variety of cellular functions including phospholipid synthesis, mitochondrial protein import, mitochondrial attachment to actin, polarized mitochondrial movement into daughter cells during division, and maintenance of mitochondrial DNA (mtDNA). The mitochondrial-anchored Gem1 GTPase has been proposed to regulate ERMES functions. Here, we show that ERMES and Gem1 have no direct role in the transport of phosphatidylserine (PS) from the ER to mitochondria during the synthesis of phosphatidylethanolamine (PE), as PS to PE conversion is not affected in ERMES or gem1 mutants. In addition, we report that mitochondrial inheritance defects in ERMES mutants are a secondary consequence of mitochondrial morphology defects, arguing against a primary role for ERMES in mitochondrial association with actin and mitochondrial movement. Finally, we show that ERMES complexes are long-lived, and do not depend on the presence of Gem1. Our findings suggest that the ERMES complex may have primarily a structural role in maintaining mitochondrial morphology.

Published
2012

Catalog

Books, media, physical & digital resources
See catalog results