title: Macromolecular complexes as depots for releasable regulatory proteins.
abstract: Multi-component, macromolecular complexes perform essential cellular functions that require spatial or temporal coordination of activities. Complexes also facilitate co-regulation of protein amounts and cellular localization of individual components. We propose a novel function of multi-component complexes as depots for regulatory proteins that, upon release, acquire new auxiliary functions. We further propose that component release is inducible and context-dependent. We describe two cases in which multi-component assemblies - the ribosome and tRNA multi-synthetase complex--function as depots. Both complexes have crucial roles in supporting protein synthesis but they also release regulatory proteins for inflammation-responsive, transcript-specific translational control. Recent evidence indicates that other macromolecular assemblies might be sources for proteins with auxiliary functions, and the depot mechanism might be widespread in nature.
authors.affiliation: Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC10, Cleveland, OH 44195, USA.
authors.forename: Partho Sarothi
authors.initials: PS
authors.lastname: Ray
authors.forename: Abul
authors.initials: A
authors.lastname: Arif
authors.forename: Paul L
authors.initials: PL
authors.lastname: Fox
mesh_terms: D000818:Animals; D006801:Humans; D008954:Models, Biological; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D014176:Protein Biosynthesis; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism
chemical_list: D046912:Multiprotein Complexes; D011506:Proteins