Localization of Furin to the trans-Golgi Network and Recycling from the Cell Surface Involves Ser and Tyr Residues within the Cytoplasmic Domain (*)
Localization of Furin to the trans-Golgi Network and Recycling from the Cell Surface Involves Ser and Tyr Residues within the Cytoplasmic Domain (*)
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弗林蛋白酶定位于跨高尔基体网络并从细胞表面回收涉及细胞质域内的 Ser 和 Tyr 残基 (*)
DOI：
10.1074/jbc.270.47.28397
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
K. Nakayama
中科院分区：
文献类型：
--
作者：
Senye Takahashi;T. Nakagawa;T. Banno;Tsuyoshi Watanabe;K. Murakami;K. Nakayama
弗林蛋白酶是一种膜结合内切蛋白酶，催化前体蛋白在Arg-X-Lys/Arg-Arg位点的切割。虽然在稳态下，弗林蛋白酶主要存在于高尔基体网络（TGN）中，但它也在TGN和细胞表面之间循环。最近，弗林蛋白酶的胞质尾已被证明是足够的本地化TGN。在胞质结构域中，有丝氨酸残基，我们现在显示的是酪蛋白激酶II在体外磷酸化的位点，和一个含酪氨酸的序列，这两者都已被证明是重要的其他TGN蛋白定位到这个隔间。在本研究中，我们通过定点突变表明，这些残基是重要的TGN定位和回收弗林蛋白酶。Ser残基的突变取消了TGN定位。相反，Tyr残基的突变不影响TGN定位，但损害了从质膜的内化。这些观察结果表明，不同的细胞质决定因素是负责保留在TGN和检索从细胞表面的弗林蛋白酶。
Furin is a membrane-associated endoprotease that catalyzes cleavage of precursor proteins at Arg-X-Lys/Arg-Arg sites. Although, at steady state, furin is predominantly found in the trans-Golgi network (TGN), it also cycles between the TGN and the cell surface. Recently, the cytoplasmic tail of furin has been shown to be sufficient for its localization to the TGN. Within the cytoplasmic domain, there are Ser residues, which we now show are sites for phosphorylation by casein kinase II in vitro, and a Tyr-containing sequence, both of which have been shown to be important for other TGN proteins to localize to this compartment. In the present study, we show by site-directed mutagenesis that these residues are important for TGN localization and recycling of furin. Mutation of the Ser residues abrogated the TGN localization. By contrast, mutation of the Tyr residue did not affect the TGN localization but impaired the internalization from the plasma membrane. These observations suggest that distinct cytoplasmic determinants are responsible for retention in the TGN and retrieval from the cell surface of furin.