Tip loci: six Chlamydomonas nuclear suppressors that permit the translocation of proteins with mutant thylakoid signal sequences.
Tip loci: six Chlamydomonas nuclear suppressors that permit the translocation of proteins with mutant thylakoid signal sequences.
复制标题
尖端基因座：六个衣藻核抑制子，允许具有突变类囊体信号序列的蛋白质易位。
DOI：
10.1093/genetics/149.3.1293
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发表时间：
1998
期刊：
影响因子：
3.3
通讯作者：
Kohorn,BD
中科院分区：
文献类型：
--
作者：
Bernd,KK;Kohorn,BD
衣原体细胞色素f（cytf）信号序列内的突变抑制类囊体膜蛋白易位，使细胞非光合作用。选择了27个突变信号序列的抑制子，以恢复光合自养生长的能力，这些抑制子描述了6个核基因座，命名为tip 1至6，用于类囊体插入蛋白。尖端突变恢复了cytf的易位，并且不是等位基因特异性的，因为它们抑制了许多不同的cytf信号序列突变。Tip5和Tip2可能在Cytf易位的早期起作用，而Tip1、Tip3、Tip4和Tip6则较晚起作用。在没有信号序列突变的情况下，tip突变没有表型，并且tip4和tip5之间存在遗传相互作用，表明它们编码的蛋白质之间存在相互作用。由于核和叶绿体编码的类囊体蛋白易位的能量、生化和遗传要求存在重叠，因此尖端突变可能识别一般类囊体蛋白易位装置的组成部分。
Mutations within the signal sequence of cytochrome f (cytf) in Chlamydomonas inhibit thylakoid membrane protein translocation and render cells nonphotosynthetic. Twenty-seven suppressors of the mutant signal sequences were selected for their ability to restore photoautotrophic growth and these describe six nuclear loci named tip1 through 6 for thylakoid insertion protein. The tip mutations restore the translocation of cytf and are not allele specific, as they suppress a number of different cytf signal sequence mutations. Tip5 and 2 may act early in cytf translocation, while Tip1, 3, 4, and 6 are engaged later. The tip mutations have no phenotype in the absence of a signal sequence mutation and there is genetic interaction between tip4, and tip5 suggesting an interaction of their encoded proteins. As there is overlap in the energetic, biochemical and genetic requirements for the translocation of nuclear and chloroplast-encoded thylakoid proteins, the tip mutations likely identify components of a general thylakoid protein translocation apparatus.