Hofmann Wilma A, Arduini Alessandro, Nicol Samantha M, Camacho Carlos J, Lessard James L, Fuller-Pace Frances V, de Lanerolle Primal
Department of Physiology and Biophysics, University of Illinois at Chicago, Chicago, IL 60612, USA.
J Cell Biol. 2009 Jul 27;186(2):193-200. doi: 10.1083/jcb.200905016.
Actin, a major component of the cytoplasm, is also abundant in the nucleus. Nuclear actin is involved in a variety of nuclear processes including transcription, chromatin remodeling, and intranuclear transport. Nevertheless, the regulation of nuclear actin by posttranslational modifications has not been investigated. We now show that nuclear actin is modified by SUMO2 and SUMO3 and that computational modeling and site-directed mutagenesis identified K68 and K284 as critical sites for SUMOylating actin. We also present a model for the actin-SUMO complex and show that SUMOylation is required for the nuclear localization of actin.
肌动蛋白是细胞质的主要成分，在细胞核中也大量存在。核肌动蛋白参与多种核过程，包括转录、染色质重塑和核内运输。然而，翻译后修饰对核肌动蛋白的调控尚未得到研究。我们现在表明，核肌动蛋白被SUMO2和SUMO3修饰，并且通过计算建模和定点诱变确定K68和K284是肌动蛋白SUMO化的关键位点。我们还提出了肌动蛋白-SUMO复合物的模型，并表明SUMO化是肌动蛋白核定位所必需的。
