The membrane targeting and spatial activation of Src, Yes and Fyn is influenced by palmitoylation and distinct RhoB/RhoD endosome requirements
The membrane targeting and spatial activation of Src, Yes and Fyn is influenced by palmitoylation and distinct RhoB/RhoD endosome requirements
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DOI：
10.1242/jcs.003657
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发表时间：
2007-08-01
影响因子：
4
通讯作者：
Frame, Margaret C.
中科院分区：
文献类型：
--
作者：
Sandilands, Emma;Brunton, Valerie G.;Frame, Margaret C.
Src激活是一个严格调控的过程，需要RhoB内体相关的肌动蛋白组装和转运到细胞外周。我们在这里表明，虽然其他两个普遍存在的Src家族激酶（SFKs）是和Fyn也需要完整的肌动蛋白丝外周膜靶向，他们显示不同的空间激活和内体的要求。与Src不同，Yes和Fyn都在一定程度上组成性膜定位，并且Fyn存在于RhoD阳性内体中，而Yes不与内体标记物RhoB或RhoD中的任一个明显共定位。通过调节Src、Yes和Fyn中棕榈酰化的氨基酸受体位点，我们发现Src S3 C/S6 C（与野生型Src不同）的棕榈酰化行为与Fyn的行为更相似，主要是与RhoD内体共定位，并且Fyn和Src S3 C/S6 C的靶向都受到siRNA介导的RhoD敲低的抑制。此外，不再棕榈酰化的Fyn C3 S/C6 S通过与RhoB内体共定位以及通过需要RhoB进行活化和膜易位而表现得更像Src。这些数据表明，空间激活和膜传递的不同模式，至少部分在特定的酰化连接序列和内体亚型要求的控制下，定义了三种普遍表达的SFK的不同特性。
Src activation is a tightly regulated process which requires RhoB endosome-associated actin assembly and transit to the cell periphery. We show here that although two other ubiquitous Src family kinases ( SFKs) Yes and Fyn also require intact actin filaments for peripheral membrane targeting, they display distinct spatial activation and endosomal requirements. Unlike Src, both Yes and Fyn are constitutively membrane-localized to some extent, and Fyn is present in RhoD-positive endosomes whereas Yes does not visibly colocalize with either of the endosomal markers RhoB or RhoD. By modulating amino acid acceptor sites for palmitoylation in Src, Yes and Fyn, we show that Src S3C/S6C, which is palmitoylated ( unlike wild-type Src) behaves in a manner more similar to Fyn, by predominantly colocalizing with RhoD endosomes, and the targeting of both Fyn and Src S3C/S6C is inhibited by siRNA-mediated knockdown of RhoD. Moreover, Fyn C3S/C6S, which is no longer palmitoylated, behaves much more like Src by colocalizing with RhoB endosomes and by requiring RhoB for activation and membrane translocation. These data imply that distinct modes of spatial activation and membrane delivery, at least partly under the control of specific acylation attachment sequences and endosome sub-type requirements, define distinct properties of the three ubiquitously expressed SFKs.