title: Structural domains of vault proteins: a role for the coiled coil domain in vault assembly.
abstract: Vaults consist of multiple copies of three proteins (MVP, VPARP, and TEP1) and several untranslated RNAs. The function of vaults is unknown but the typical and evolutionary conserved structure indicates a role in intracellular transport. Although all vault components have been identified and characterized, not much is known about vault protein assembly. In this study we identified and analyzed structural domains involved in vault assembly with emphasis on protein-protein interactions. Using a yeast two-hybrid system, we demonstrate within MVP an intramolecular binding site and show that MVP molecules interact with each other via their coiled coil domain. We show that purified MVP is able to bind calcium, most likely at calcium-binding EF-hands. No interactions could be detected between TEP1 and other vault proteins. However, the N-terminal half of MVP binds to a specific domain in the C-terminus of VPARP. Furthermore, VPARP contains amino acid stretches mediating intramolecular binding.
authors.affiliation: Institute of Hematology, Erasmus University, Rotterdam, The Netherlands.
authors.forename: Arend
authors.initials: A
authors.lastname: van Zon
authors.forename: Marieke H
authors.initials: MH
authors.lastname: Mossink
authors.forename: Martijn
authors.initials: M
authors.lastname: Schoester
authors.forename: George L
authors.initials: GL
authors.lastname: Scheffer
authors.forename: Rik J
authors.initials: RJ
authors.lastname: Scheper
authors.forename: Pieter
authors.initials: P
authors.lastname: Sonneveld
authors.forename: Erik A C
authors.initials: EA
authors.lastname: Wiemer
mesh_terms: D000595:Amino Acid Sequence; D002118:Calcium / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism; D020832:EF Hand Motifs; D046911:Macromolecular Substances; D008954:Models, Biological; D008969:Molecular Sequence Data; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques; D020394:Vault Ribonucleoprotein Particles / Q000737:chemistry* / Q000378:metabolism*; D000099187:Major Vault Protein
chemical_list: D002118:Calcium; D002352:Carrier Proteins; D046911:Macromolecular Substances; D011065:Poly(ADP-ribose) Polymerases; D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein; C449359:vault poly(ADP-ribose) polymerase