Palmitoylation of p59fyn is reversible and sufficient for plasma membrane association.
Palmitoylation of p59fyn is reversible and sufficient for plasma membrane association.
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DOI：
10.1091/mbc.8.6.1159
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发表时间：
1997-06
影响因子：
3.3
通讯作者：
Amy Wolven;Heidi;Okamura;Yael;Rosenblatt;Marilyn;-D.;Resh
中科院分区：
文献类型：
--
作者：
Amy Wolven;Heidi;Okamura;Yael;Rosenblatt;Marilyn;-D.;Resh
Src蛋白酪氨酸激酶家族的成员定位于质膜的亚专门化区域。本研究表明，Src家族成员p59fyn （Fyn）的n端SH4区域对于Fyn和异源蛋白靶向质膜和洗涤剂不溶性亚结构域既是必要的，也是充分的。Fyn的前16个氨基酸附着在正常胞质蛋白-半乳糖苷酶上，导致嵌合蛋白的质膜定位。fyn16 -半乳糖苷酶中的棕榈酰化位点（半胱氨酸-3）或野生型Fyn的突变取消了质膜定位，导致突变蛋白重新分布到细胞膜内。Fyn中的SH4基序被其他棕榈酰化蛋白（G α o和GAP43）的异源序列取代，表明棕榈酸盐的存在足以指导质膜定位，而不依赖于周围的氨基酸序列和肉豆酸盐。在Triton x -100抗性基质中也富集了棕榈酰化的Fyn嵌合体，而在洗涤剂可溶性部分中检测到这些蛋白的非棕榈酰化形式。Fyn上棕榈酸酯部分的半衰期为1.5 ~ 2 h，而多肽主链的半衰期为8 h，表明棕榈酰化是一个可逆修饰。这些研究表明，Fyn的棕榈酰化SH4序列可以以可逆的方式特异性靶向蛋白到质膜上。
Members of the Src family of protein tyrosine kinases are localized to subspecialized regions of the plasma membrane. Herein we show that the N-terminal SH4 region of the Src family member p59fyn (Fyn) is both necessary and sufficient for targeting of Fyn and heterologous proteins to the plasma membrane and detergent-insoluble subdomains. Attachment of the first 16 amino acids of Fyn to a normally cytosolic protein, beta-galactosidase, resulted in distinct plasma membrane localization of the chimeric protein. Mutation of the palmitoylation site (cysteine-3) within Fyn16-beta-galactosidase or wild-type Fyn abrogated plasma membrane localization, resulting in redistribution of the mutant proteins into intracellular membranes. Substitution of the SH4 motif within Fyn with heterologous sequences from other palmitoylated proteins (G alpha o and GAP43) revealed that the presence of palmitate is sufficient to direct plasma membrane localization independent of surrounding amino acid sequences and myristate. Palmitoylated Fyn chimeras were also enriched in the Triton X-100-resistant matrix, whereas nonpalmitoylated forms of these proteins were detected in the detergent-soluble fraction. The palmitate moiety on Fyn exhibited a half-life of 1.5-2 h. In contrast, the half-life of the polypeptide backbone was 8 h, indicating that palmitoylation is a reversible modification. These studies establish that the palmitoylated SH4 sequence of Fyn can be used to specifically target proteins to the plasma membrane in a reversible manner.