Macromolecular complexes as depots for releasable regulatory proteins.
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.
Ray
Partho Sarothi
PS
Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, 9500 Euclid Avenue/NC10, Cleveland, OH 44195, USA.
Arif
Abul
A
Fox
Paul L
PL
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
D046912:Multiprotein Complexes; D011506:Proteins