The role of ubiquitin in down-regulation and intracellular sorting of membrane proteins: insights from yeast.
Ubiquitination is a versatile tool used by all eukaryotic organisms for controlling the stability, function, and intracellular localization of a wide variety of proteins. Two of the best characterized functions of protein ubiquitination are to mark proteins for degradation by cytosolic proteasome and to promote the internalization of certain plasma membrane proteins via the endocytotic pathway, followed by their degradation in the vacuole. Recent studies of membrane proteins both in yeast and mammalian cells suggest that the role of ubiquitin may extend beyond its function as an internalization signal in that it also may be required for modification of some component(s) of the endocytotic machinery, and for cargo protein sorting at the late endosome and the Golgi apparatus level. In this review, I will attempt to bring together what is currently known about the role of ubiquitination in controlling protein trafficking between the yeast plasma membrane, the trans-Golgi network, and the vacuole/lysosome.
Horák
Jaroslav
J
Department of Membrane Transport, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague, Czech Republic. horak@biomed.cas.cz
D015536:Down-Regulation; D004705:Endocytosis; D056827:Endosomal Sorting Complexes Required for Transport; D007425:Intracellular Membranes / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000502:physiology; D025801:Ubiquitin / Q000502:physiology*; D043743:Ubiquitin-Protein Ligase Complexes / Q000737:chemistry / Q000502:physiology
D056827:Endosomal Sorting Complexes Required for Transport; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; D043743:Ubiquitin-Protein Ligase Complexes; C469287:RSP5 protein, S cerevisiae