Disruption of an RNA helicase/RNAse III gene in Arabidopsis causes unregulated cell division in floral meristems.
Disruption of an RNA helicase/RNAse III gene in Arabidopsis causes unregulated cell division in floral meristems.
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发表时间：
1999-12
期刊：
影响因子：
4.6
通讯作者：
S. Jacobsen;M. Running;E. Meyerowitz
中科院分区：
文献类型：
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作者：
S. Jacobsen;M. Running;E. Meyerowitz
拟南芥花分生组织是确定的结构，产生一定数量的器官，之后细胞分裂停止。一个新的隐性突变体，心皮工厂（caf），将花的分生组织转化为不确定状态。它们产生额外的雄蕊轮生和无限数量的心皮。因此，CAF似乎抑制了花分生组织中的细胞分裂。CAF基因的功能与CLAVATA （CLV）和SUPERMAN （SUP）基因的功能部分重叠，因为CAF - CLV和CAF - SUP双突变体显著增强了花分生组织的过度增殖。Caf突变植株还表现出其他缺陷，包括缺乏腋生花序分生组织，叶片和花器官形状异常。克隆了CAF基因，发现其编码一个1909个氨基酸的推测蛋白，该蛋白含有一个n端DExH/DEAD-box型RNA解旋酶结构域和一个c端RNaseIII-like结构域。真菌和动物的基因组编码了一种功能未知的非常相似的蛋白质。解旋酶蛋白参与许多过程，包括特异性mRNA定位和mRNA剪接。RNase III蛋白参与rRNA和一些mRNA分子的加工。因此，CAF可能通过某种类型的RNA加工事件起作用。CAF产生两个主要转录本，分别为2.5 kb和6.2 kb。原位杂交实验表明，CAF RNA在所有茎组织中均有表达。
Arabidopsis thaliana floral meristems are determinate structures that produce a defined number of organs, after which cell division ceases. A new recessive mutant, carpel factory (caf), converts the floral meristems to an indeterminate state. They produce extra whorls of stamens, and an indefinite number of carpels. Thus, CAF appears to suppress cell division in floral meristems. The function of CAF is partially redundant with the function of the CLAVATA (CLV) and SUPERMAN (SUP) genes, as caf clv and caf sup double mutants show dramatically enhanced floral meristem over-proliferation. caf mutant plants also show other defects, including absence of axillary inflorescence meristems, and abnormally shaped leaves and floral organs. The CAF gene was cloned and found to encode a putative protein of 1909 amino acids containing an N-terminal DExH/DEAD-box type RNA helicase domain attached to a C-terminal RNaseIII-like domain. A very similar protein of unknown function is encoded by a fungal and an animal genome. Helicase proteins are involved in a number of processes, including specific mRNA localization and mRNA splicing. RNase III proteins are involved in the processing of rRNA and some mRNA molecules. Thus CAF may act through some type of RNA processing event(s). CAF gives rise to two major transcripts of 2.5 and 6.2 kb. In situ hybridization experiments show that CAF RNA is expressed throughout all shoot tissues.