Control of cell division by a retinoblastoma protein homolog in Chlamydomonas
Control of cell division by a retinoblastoma protein homolog in Chlamydomonas
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DOI：
10.1101/gad.892101
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发表时间：
2001-07-01
影响因子：
10.5
通讯作者：
Goodenough, UW
中科院分区：
文献类型：
--
作者：
Umen, JG;Goodenough, UW
在动物细胞中控制细胞分裂和分化的一个关键途径是视网膜母细胞瘤(Rb)抑癌基因家族，该家族调控细胞从G期到S期和S期。RE途径在植物中的作用(S)还没有明确的定义，也没有任何证据表明它存在于单细胞生物体中。在这里，我们已经在陆地植物谱系中的单细胞绿藻莱茵衣藻中鉴定出一个由mat3基因编码的RE同源物。衣藻细胞通常在长时间的G期内生长到原始大小的数倍，然后经历多轮交替的S期和有丝分裂，产生大小一致的子细胞。Mat3突变体产生小的子细胞，并在两个大小相关的细胞周期控制中显示出缺陷：它们以低于正常大小的大小启动细胞周期，并经历额外的S期/有丝分裂。与哺乳动物RE突变体不同，Mat3突变体没有缩短的G_1，不会过早进入S期，可以退出细胞周期，正常分化，表明衣藻的RE途径与动物的作用不同。
A key pathway that controls both cell division and differentiation in animal cells is mediated by the retinoblastoma (RB) family of tumor suppressors, which gate the passage of cells from G, to S and through S phase. The role(s) of the RE pathway in plants are not yet clearly defined, nor has there been any evidence for its presence in unicellular organisms. Here we have identified an RE homolog encoded by the mat3 gene in Chlamydomonas reinhardtii, a unicellular green alga in the land plant lineage. Chlamydomonas cells normally grow to many times their original size during a prolonged G, and then undergo multiple alternating rounds of S phase and mitosis to produce daughter cells of uniform size. mat3 mutants produce small daughter cells and show defects in two size-dependent cell cycle controls: They initiate the cell cycle at a below-normal size, and they undergo extra rounds of S phase/mitosis. Unlike mammalian RE mutants, mat3 mutants do not have a shortened G,, do not enter S phase prematurely, and can exit the cell cycle and differentiate normally, indicating that the RE pathway in Chlamydomonas has a different role than in animals.