title: Evolution of a signalling system that incorporates both redundancy and diversity: Arabidopsis SUMOylation.
abstract: The reversible post-translational modifier, SUMO (small ubiquitin-related modifier), modulates the activity of a diverse set of target proteins, resulting in important consequences to the cellular machinery. Conjugation machinery charges the processed SUMO so that it can be linked via an isopeptide bond to a target protein. The removal of SUMO moieties from conjugated proteins by isopeptidases regenerates pools of processed SUMOs and unmodified target proteins. The evolutionarily conserved SUMO-conjugating proteins, E1 and E2, recognize a diverse set of Arabidopsis SUMO proteins using them to modify protein substrates. In contrast, the deSUMOylating enzymes differentially recognize the Arabidopsis SUMO proteins, resulting in specificity of the deconjugating machinery. The specificity of the Arabidopsis deSUMOylating enzymes is further diversified by the addition of regulatory domains. Therefore the SUMO proteins, in this signalling system, have evolved to contain information that allows not only redundancy with the conjugation system but also diversity with the deconjugating enzymes.
authors.affiliation: Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA.
authors.forename: Renee
authors.initials: R
authors.lastname: Chosed
authors.forename: Sohini
authors.initials: S
authors.lastname: Mukherjee
authors.forename: Luisa Maria
authors.initials: LM
authors.lastname: Lois
authors.forename: Kim
authors.initials: K
authors.lastname: Orth
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000378:metabolism*; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000378:metabolism; D019143:Evolution, Molecular; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D015398:Signal Transduction; D014452:Ubiquitins / Q000737:chemistry / Q000378:metabolism*
chemical_list: C403233:SUMO protein, plant; D014452:Ubiquitins; D003546:Cysteine Endopeptidases; C118083:Ulp1 protease