Stursberg S, Riwar B, Jessberger R
Basel Institute for Immunology, Grenzacherstr. 487, CH-4005, Basel, Switzerland.
Gene. 1999 Mar 4;228(1-2):1-12. doi: 10.1016/s0378-1119(99)00021-9.
Members of the evolutionary conserved Structural Maintenance of Chromosomes (SMC) protein family are involved in chromosome condensation and gene dosage compensation with the SMC2 and SMC4 subtypes, and sister chromatid cohesion with the SMC1 and SMC3 subtypes. The bovine recombination protein complex RC-1, which catalyzes DNA transfer reactions, contains two heterodimeric SMC polypeptides, the genes of which have now been cloned, sequenced, and classified as bovine (b)SMC1 and bSMC3. Both proteins display all the characteristic features of the SMC family. FISH analysis localized the mouse SMC3 gene to chromosome 19D2-D3. Mono- and polyclonal antibodies specific for either subtype detected high levels of protein expression in lymphoid tissues, lung, testis and ovary. No change in levels of bSMC1 and bSMC3 proteins occurred after X-ray or UV-light irradiation of various cell lines or primary cells, and the amounts of individual proteins and the heterodimer are roughly constant throughout the cell cycle. Immunofluorescence of mouse cells detected the SMC1 protein in foci associated with the chromatin. These foci dissolve and the SMC protein dissociates from the chromatin during M phase.
进化保守的染色体结构维持（SMC）蛋白家族成员参与染色体浓缩以及与SMC2和SMC4亚型相关的基因剂量补偿，还参与与SMC1和SMC3亚型相关的姐妹染色单体黏连。牛重组蛋白复合物RC-1催化DNA转移反应，它包含两个异二聚体SMC多肽，其基因现已被克隆、测序，并归类为牛（b）SMC1和bSMC3。这两种蛋白质都具有SMC家族的所有特征。荧光原位杂交（FISH）分析将小鼠SMC3基因定位到19D2-D3染色体上。针对任一亚型的单克隆和多克隆抗体在淋巴组织、肺、睾丸和卵巢中检测到高水平的蛋白质表达。对各种细胞系或原代细胞进行X射线或紫外线照射后，bSMC1和bSMC3蛋白水平没有变化，并且在整个细胞周期中，单个蛋白质和异二聚体的量大致恒定。对小鼠细胞进行免疫荧光检测，发现SMC1蛋白存在于与染色质相关的病灶中。在M期，这些病灶溶解，SMC蛋白从染色质上解离。
