title: A conserved membrane-binding domain targets proteins to organelle contact sites.
abstract: Membrane contact sites (MCSs), where the membranes of two organelles are closely apposed, are regions where small molecules such as lipids or calcium are exchanged between organelles. We have identified a conserved membrane-binding domain found exclusively in proteins at MCSs in Saccharomyces cerevisiae. The synaptotagmin-like-mitochondrial-lipid binding protein (SMP) domain is conserved across species. We show that all seven proteins that contain this domain in yeast localize to one of three MCSs. Human proteins with SMP domains also localize to MCSs when expressed in yeast. The SMP domain binds membranes and is necessary for protein targeting to MCSs. Proteins containing this domain could be involved in lipid metabolism. This is the first protein domain found exclusively in proteins at MCSs.
authors.affiliation: Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892,  USA.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Toulmay
authors.forename: William A
authors.initials: WA
authors.lastname: Prinz
mesh_terms: D001343:Autophagy; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D017124:Conserved Sequence; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D050356:Lipid Metabolism; D008565:Membrane Proteins / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D015388:Organelles / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism*; D014617:Vacuoles / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; C581360:Nvj2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins