Chosed Renee, Mukherjee Sohini, Lois Luisa Maria, Orth Kim
Department of Molecular Biology, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX 75390, USA.
Biochem J. 2006 Sep 15;398(3):521-9. doi: 10.1042/BJ20060426.
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.
可逆的翻译后修饰因子小泛素相关修饰物（SUMO）可调节多种靶蛋白的活性，对细胞机制产生重要影响。缀合机制使加工后的SUMO带上电荷，从而使其能够通过异肽键与靶蛋白相连。异肽酶将SUMO部分从缀合蛋白上去除，使加工后的SUMO池和未修饰的靶蛋白得以再生。进化上保守的SUMO缀合蛋白E1和E2识别多种拟南芥SUMO蛋白，并利用它们修饰蛋白底物。相比之下，去SUMO化酶对拟南芥SUMO蛋白的识别具有差异，从而导致去缀合机制具有特异性。通过添加调控结构域，拟南芥去SUMO化酶的特异性进一步多样化。因此，在这个信号系统中，SUMO蛋白的进化使其不仅包含与缀合系统冗余的信息，还包含与去缀合酶相关的多样性信息。
