title: Signalosome assembly by domains undergoing dynamic head-to-tail polymerization.
abstract: A key mechanism for guarding against inappropriate activation of signaling molecules is their weak affinity for effectors, which prevents them from undergoing accidental signal-transducing interactions due to fluctuations in their cellular concentration. The molecular devices that overcome these weak affinities are the signalosomes: dynamic clusters of transducing molecules assembled typically at signal-activated receptors. Signalosomes contain high local concentrations of protein-binding sites, and thus have a high avidity for their low-affinity ligands that generate signal responses. This review focuses on three domains - DIX (dishevelled and axin), PB1 (Phox and Bem1), and SAM (sterile alpha motif) - that undergo dynamic head-to-tail polymerization to assemble signalosomes and similar particles that require transient high local concentrations of protein-binding sites.
authors.affiliation: Medical Research Council (MRC) Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK. Electronic address: mb2@mrc-lmb.cam.ac.uk.
authors.forename: Mariann
authors.initials: M
authors.lastname: Bienz
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology; D020559:Monomeric GTP-Binding Proteins / Q000378:metabolism; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D000076106:SAM Domain and HD Domain-Containing Protein 1; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000502:physiology*; D051153:Wnt Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D047908:Intracellular Signaling Peptides and Proteins; D051153:Wnt Proteins; D000076106:SAM Domain and HD Domain-Containing Protein 1; C484280:SAMHD1 protein, human; D020559:Monomeric GTP-Binding Proteins