THE PEROXISOMAL IMPORT SIGNAL OF AMINE OXIDASE FROM THE YEAST HANSENULA-POLYMORPHA IS NOT UNIVERSAL
THE PEROXISOMAL IMPORT SIGNAL OF AMINE OXIDASE FROM THE YEAST HANSENULA-POLYMORPHA IS NOT UNIVERSAL
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DOI：
10.1002/yea.320080402
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发表时间：
1992-04-01
期刊：
影响因子：
2.6
通讯作者：
AB, G
中科院分区：
文献类型：
--
作者：
DEHOOP, MJ;VALKEMA, R;AB, G
来自多形汉逊酵母的胺氧化酶是过氧化物酶体蛋白。蛋白质进入过氧化物酶体的信号尚未确定。突变型胺氧化酶在H.多形体已经揭示了具有内部SRL三肽的C-末端序列不参与靶向（Faber等人，未出版）。我们探索了胺氧化酶基因（AMO）在酿酒酵母中的异源表达，以研究酵母之间过氧化物酶体靶向途径的保守性。令人惊讶的是，野生型胺氧化酶不被S.啤酒。这种酶是完全活性的，积累的水平与在H. polymorpha，完全停留在胞质溶胶中。然而，将SKL或SRL序列融合到C-末端迫使蛋白质至少部分进入异源宿主的过氧化物酶体。这些数据表明胺氧化酶的功能性靶向序列可能不同于C-末端过氧化物酶体靶向信号S/C/A-K/R/H-L（Gould等人，1989).与已建立的三肽基序相反，胺氧化酶靶向信号似乎在不同酵母物种之间不保守。
Amine oxidase from the yeast Hansenula polymorpha is a peroxisomal protein. The signal for routing of the protein into peroxisomes has not been identified yet. Expression of a mutant amine oxidase in H. polymorpha has revealed that the C-terminal sequence, which possesses an internal SRL tripeptide, is not involved in targeting (Faber et al., unpublished). We have explored heterologous expression of the amine oxidase gene (AMO) in Saccharomyces cerevisiae to investigate the conservation of peroxisomal targeting pathways between yeasts. Surprisingly, wild-type amine oxidase is not recognized as a peroxisomal protein by S. cerevisiae. The enzyme, which was fully active and accumulated to levels similar to those found in H. polymorpha, stayed entirely in the cytosol. However, fusing a SKL or a SRL sequence to the C-terminus forced the protein at least partially into peroxisomes of the heterologous host. These data suggest that the functional targeting sequence of amine oxidase may differ from the C-terminal peroxisomal targeting signal S/C/A-K/R/H-L (Gould et al., 1989).Contrary to the established tripeptide motif, the amine oxidase targeting signal appears not to be conserved between the different yeast species.