The Sec14 family glycerophospholipid-transfer protein is required for structural integrity of the spindle pole body during meiosis in fission yeast
The Sec14 family glycerophospholipid-transfer protein is required for structural integrity of the spindle pole body during meiosis in fission yeast
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DOI：
10.1111/j.1365-2443.2004.00806.x
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发表时间：
2004-12-01
期刊：
影响因子：
2.1
通讯作者：
Shimoda, C
中科院分区：
文献类型：
--
作者：
Nakase, Y;Nakamura, T;Shimoda, C
裂殖酵母spo 20（+）基因编码甘油磷脂转移蛋白。spo 20突变体不能正确地组装前孢子膜。在这里，我们研究了spo 20-H6突变体在减数分裂过程中纺锤体极体（SPB）的结构完整性。表达GFP标记的SPB标记蛋白Spo 15-GFP的减数分裂细胞显示出过量的SPB，其中一些未定位于纺锤体极，被称为“假SPB”。Spo 20-H6细胞减数分裂I纺锤体的形成明显延迟，尽管纺锤体的形态和姐妹染色单体的分离似乎正常。spo 20-H6的SPB含有减数分裂特异性的外部斑块，尽管最外层不太明显。对spo 20-H6细胞的延时研究表明，假SPB起源于减数分裂I期间纺锤体两极的正常SPB。在所检测的SPB组分中，Spo 15、Spo 13、Sad 1和Cut 12定位于伪SPB，但Sid 4并不总是存在。Alp 4，γ-微管蛋白复合物的一个组成部分，也存在于约40%的假SPBs。前孢子膜起源于SPB和假SPB。我们的结论是，Spo 20起着维持减数分裂SPB的结构完整性的作用，除了提供前孢子膜组装的膜泡。
The fission yeast spo20(+) gene encodes a glycerophospholipid-transfer protein. spo20 mutants are unable to assemble the forespore membrane properly. Here we studied the structural integrity of the spindle pole body (SPB) in spo20-H6 mutants during meiosis. Meiotic cells expressing a GFP-tagged SPB marker protein, Spo15-GFP, showed an excess number of SPBs, some of which were not localized to the spindle poles and were termed 'pseudo-SPBs'. Formation of spindles for meiosis I was significantly delayed in spo20-H6 cells, although the morphology of spindles and segregation of the sister chromatids seemed normal. The SPB of spo20-H6 contained meiosis-specific outer plaques, though outermost layers were less evident. Time-lapse studies of spo20-H6 cells showed that the pseudo-SPBs originated from normal SPBs at the spindle poles during meiosis I. Among the SPB components tested, Spo15, Spo13, Sad1 and Cut12 were localized to the pseudo-SPBs, but Sid4 was not always present. Alp4, a component of the gamma-tubulin complex, was also present in about 40% of the pseudo-SPBs. The forespore membranes initiated from both the SPBs and the pseudo-SPBs. We conclude that Spo20 plays a role in maintaining the structural integrity of the meiotic SPB, besides supplying membrane vesicles for forespore membrane assembly.