Jasieniecka-Gazarkiewicz Katarzyna, Lager Ida, Carlsson Anders S, Gutbrod Katharina, Peisker Helga, Dörmann Peter, Stymne Sten, Banaś Antoni
Intercollegiate Faculty of Biotechnology, University of Gdańsk and Medical University of Gdańsk, 80-307 Gdansk, Poland (K.J.-G., A.B.).
Department of Plant Breeding, Swedish University of Agricultural Sciences, 230 53 Alnarp, Sweden (I.L., A.S.C., S.S.); and.
Plant Physiol. 2017 Jun;174(2):986-998. doi: 10.1104/pp.17.00391. Epub 2017 Apr 13.
Arabidopsis () contains two enzymes (encoded by the and genes) preferentially acylating lysophosphatidylethanolamine (LPE) with acyl-coenzyme A (CoA), designated LYSOPHOSPHATIDYLETHANOLAMINE ACYLTRANSFERASE1 (LPEAT1) and LPEAT2. The transfer DNA insertion mutant lpeat2 and the double mutant lpeat1 lpeat2 showed impaired growth, smaller leaves, shorter roots, less seed setting, and reduced lipid content per fresh weight in roots and seeds and large increases in LPE and lysophosphatidylcholine (LPC) contents in leaves. Microsomal preparations from leaves of these mutants showed around 70% decrease in acylation activity of LPE with 16:0-CoA compared with wild-type membranes, whereas the acylation with 18:1-CoA was much less affected, demonstrating that other lysophospholipid acyltransferases than the two LPEATs could acylate LPE The above-mentioned effects were less pronounced in the single lpeat1 mutant. Overexpression of either LPEAT1 or LPEAT2 under the control of the 35S promotor led to morphological changes opposite to what was seen in the transfer DNA mutants. Acyl specificity studies showed that LPEAT1 utilized 16:0-CoA at the highest rate of 11 tested acyl-CoAs, whereas LPEAT2 utilized 20:0-CoA as the best acyl donor. Both LPEATs could acylate either position of ether analogs of LPC The data show that the activities of LPEAT1 and LPEAT2 are, in a complementary way, involved in growth regulation in Arabidopsis. It is shown that LPEAT activity (especially LPEAT2) is essential for maintaining adequate levels of phosphatidylethanolamine, LPE, and LPC in the cells.
拟南芥含有两种酶（由LPEAT1和LPEAT2基因编码），它们优先用酰基辅酶A（CoA）将溶血磷脂酰乙醇胺（LPE）酰化，分别命名为溶血磷脂酰乙醇胺酰基转移酶1（LPEAT1）和LPEAT2。转移DNA插入突变体lpeat2和双突变体lpeat1 lpeat2表现出生长受损、叶片变小、根变短、结实率降低，根和种子中每鲜重的脂质含量减少，叶片中LPE和溶血磷脂酰胆碱（LPC）含量大幅增加。与野生型膜相比，这些突变体叶片的微粒体制剂显示，LPE与16:0-CoA的酰化活性降低了约70%，而与18:1-CoA的酰化受影响较小，这表明除了这两种LPEATs之外的其他溶血磷脂酰基转移酶也可以将LPE酰化。上述影响在单一的lpeat1突变体中不太明显。在35S启动子控制下过表达LPEAT1或LPEAT2会导致与转移DNA突变体相反的形态变化。酰基特异性研究表明，LPEAT1在11种测试的酰基辅酶A中以最高速率利用16:0-CoA，而LPEAT2以20:0-CoA作为最佳酰基供体。两种LPEATs都可以将LPC的醚类似物的任一位置酰化。数据表明，LPEAT1和LPEAT2的活性以互补的方式参与拟南芥的生长调节。结果表明，LPEAT活性（尤其是LPEAT2）对于维持细胞中磷脂酰乙醇胺、LPE和LPC的适当水平至关重要。
