Gould S J, Keller G A, Subramani S
Department of Biology, University of California, San Diego, La Jolla 92093.
J Cell Biol. 1988 Sep;107(3):897-905. doi: 10.1083/jcb.107.3.897.
As part of an effort to understand how proteins are imported into the peroxisome, we have sought to identify the peroxisomal targeting signals in four unrelated peroxisomal proteins: human catalase, rat hydratase:dehydrogenase, pig D-amino acid oxidase, and rat acyl-CoA oxidase. Using gene fusion experiments, we have identified a region of each protein that can direct heterologous proteins to peroxisomes. In each case, the peroxisomal targeting signal is contained at or near the carboxy terminus of the protein. For catalase, the peroxisomal targeting signal is located within the COOH-terminal 27 amino acids of the protein. For hydratase:dehydrogenase, D-amino acid oxidase, and acyl-CoA oxidase, the targeting signals are located within the carboxy-terminal 15, 14, and 15 amino acids, respectively. A tripeptide of the sequence Ser-Lys/His-Leu is present in each of these targeting signals as well as in the peroxisomal targeting signal identified in firefly luciferase (Gould, S.J., G.-A. Keller, and S. Subramani. 1987. J. Cell Biol. 105:2923-2931). When the peroxisomal targeting signal of the hydratase:dehydrogenase is mutated so that the Ser-Lys-Leu tripeptide is converted to Ser-Asn-Leu, it can no longer direct proteins to peroxisomes. We suggest that this tripeptide is an essential element of at least one class of peroxisomal targeting signals.
作为了解蛋白质如何导入过氧化物酶体的研究工作的一部分，我们试图在四种不相关的过氧化物酶体蛋白中鉴定过氧化物酶体靶向信号：人过氧化氢酶、大鼠水化酶：脱氢酶、猪D-氨基酸氧化酶和大鼠酰基辅酶A氧化酶。通过基因融合实验，我们确定了每种蛋白质中可将异源蛋白导向过氧化物酶体的区域。在每种情况下，过氧化物酶体靶向信号都位于蛋白质的羧基末端或其附近。对于过氧化氢酶，过氧化物酶体靶向信号位于该蛋白质羧基末端的27个氨基酸内。对于水化酶：脱氢酶、D-氨基酸氧化酶和酰基辅酶A氧化酶，靶向信号分别位于羧基末端的15、14和15个氨基酸内。这些靶向信号中的每一个以及在萤火虫荧光素酶中鉴定出的过氧化物酶体靶向信号（古尔德，S.J.，G.-A.凯勒和S.苏布拉马尼。1987年。《细胞生物学杂志》105:2923 - 2931）中都存在序列为Ser-Lys/His-Leu的三肽。当水化酶：脱氢酶的过氧化物酶体靶向信号发生突变，使得Ser-Lys-Leu三肽转变为Ser-Asn-Leu时，它就不再能将蛋白质导向过氧化物酶体。我们认为这种三肽是至少一类过氧化物酶体靶向信号的基本元件。
