Protein kinase Cη is targeted to lipid droplets
Protein kinase Cη is targeted to lipid droplets
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DOI：
10.1007/s00418-013-1083-z
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发表时间：
2013-02
影响因子：
2.3
通讯作者：
Michitaka Suzuki;Yuri Iio;N. Saito;T. Fujimoto
中科院分区：
文献类型：
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作者：
Michitaka Suzuki;Yuri Iio;N. Saito;T. Fujimoto
蛋白激酶C （PKC）是一个调节许多细胞功能的激酶家族。它们被分为三个亚家族，即传统PKCs、新型PKCs和非典型PKCs，它们具有不同的结构域结构。一般来说，PKCs作为一种可溶性蛋白存在于静息细胞的细胞质中，它们在受到刺激时被招募到靶膜上。在本研究中，我们发现带有EGFP标记的PKCη分布在脂滴（LD）中，并诱导LD大小显著减少。另外两个新的PKCs PKCδ和PKCε也在ld周围有一定的集中，但与PKCη相比不那么明显和频繁。传统和非典型PKCs （α, βII， γ和ζ）在ld周围没有表现出任何优先分布。1,2-二酰基甘油可以在不增加Ca2+浓度的情况下激活新的PKCs，是三酰基甘油的直接前体，存在于ld中。目前的结果表明PKCη通过磷酸化ld中未知的靶点来改变脂质代谢。
Protein kinase C (PKC) is a family of kinases that regulate numerous cellular functions. They are classified into three subfamilies, i.e., conventional PKCs, novel PKCs, and atypical PKCs, that have different domain structures. Generally, PKCs exist as a soluble protein in the cytosol in resting cells and they are recruited to target membranes upon stimulation. In the present study, we found that PKCη tagged with EGFP distributed in lipid droplets (LD) and induced a significant reduction in LD size. Two other novel PKCs, PKCδ and PKCε, also showed some concentration around LDs, but it was less distinct and less frequent than that of PKCη. Conventional and atypical PKCs (α, βII, γ, and ζ) did not show any preferential distribution around LDs. 1,2-Diacylglycerol, which can activate novel PKCs without an increase of Ca2+concentration, is the immediate precursor of triacylglycerol and exists in LDs. The present results suggest that PKCη modifies lipid metabolism by phosphorylating unidentified targets in LDs.