Rho2 Palmitoylation Is Required for Plasma Membrane Localization and Proper Signaling to the Fission Yeast Cell Integrity Mitogen-Activated Protein Kinase Pathway
Rho2 Palmitoylation Is Required for Plasma Membrane Localization and Proper Signaling to the Fission Yeast Cell Integrity Mitogen-Activated Protein Kinase Pathway
复制标题
DOI：
10.1128/mcb.01515-13
复制
发表时间：
2014-05
影响因子：
5.3
通讯作者：
Laura Sánchez-Mir;A. Franco;R. Martín-García;Marisa Madrid;J. Vicente-Soler;T. Soto;M. Gacto;P. Pérez;J. Cansado
中科院分区：
文献类型：
--
作者：
Laura Sánchez-Mir;A. Franco;R. Martín-García;Marisa Madrid;J. Vicente-Soler;T. Soto;M. Gacto;P. Pérez;J. Cansado
分裂酵母小GTPase Rho2调节形态发生，是细胞完整性通路的上游激活因子，其关键元件有丝分裂原激活蛋白激酶（MAPK） Pmk1在多种环境刺激下被激活并控制多种细胞功能。在这里，我们证明了法酰化的Rho2在体内在其羧基端半胱氨酸-196处变成棕榈酰化，并且这种修饰允许其特异性靶向质膜。与其他棕榈酰化和戊酰化gtpase不同，Rho2对形态发生和Pmk1活性的控制严格依赖于质膜定位，在其他细胞膜中没有发现。事实上，人工质膜靶向绕过了Rho2对棕榈酰化的需要来发出信号。从必需GTPase Rho1融合到羧基端的Rho2嵌合体的详细功能分析表明，GTPase棕榈酰化部分依赖于戊烯酰化背景，并证实Rho2信号传导独立于Rho GTP解离抑制剂（GDI）功能。我们进一步证明Rho2是DHHC家族酰基转移酶Erf2棕榈酰转移酶的体内底物。值得注意的是，另一个Erf2靶点Rho3以rho2不依赖的方式负调控Pmk1的活性，从而揭示了两种gtpase拮抗调节MAPK级联活性的串扰的存在。
ABSTRACT The fission yeast small GTPase Rho2 regulates morphogenesis and is an upstream activator of the cell integrity pathway, whose key element, mitogen-activated protein kinase (MAPK) Pmk1, becomes activated by multiple environmental stimuli and controls several cellular functions. Here we demonstrate that farnesylated Rho2 becomes palmitoylated in vivo at cysteine-196 within its carboxyl end and that this modification allows its specific targeting to the plasma membrane. Unlike that of other palmitoylated and prenylated GTPases, the Rho2 control of morphogenesis and Pmk1 activity is strictly dependent upon plasma membrane localization and is not found in other cellular membranes. Indeed, artificial plasma membrane targeting bypassed the Rho2 need for palmitoylation in order to signal. Detailed functional analysis of Rho2 chimeras fused to the carboxyl end from the essential GTPase Rho1 showed that GTPase palmitoylation is partially dependent on the prenylation context and confirmed that Rho2 signaling is independent of Rho GTP dissociation inhibitor (GDI) function. We further demonstrate that Rho2 is an in vivo substrate for DHHC family acyltransferase Erf2 palmitoyltransferase. Remarkably, Rho3, another Erf2 target, negatively regulates Pmk1 activity in a Rho2-independent fashion, thus revealing the existence of cross talk whereby both GTPases antagonistically modulate the activity of this MAPK cascade.