Leung D W
Cell Therapeutics, Inc., Seattle, WA 98119, USA.
Front Biosci. 2001 Aug 1;6:D944-53. doi: 10.2741/leung.
Lysophosphatidic acid (LPA) and phosphatidic acid (PA) are two phospholipids involved in signal transduction and in lipid biosynthesis in cells. LPA acyltransferase (LPAAT), also known as 1-acyl sn-glycerol-3-phosphate acyltransferase (1-AGPAT) (EC 2.3.1.51), catalyzes the conversion of LPA to PA. Two human isoforms of LPAAT, designated as LPAAT-alpha (AGPAT1) and LPAAT-beta (AGPAT2), have been extensively characterized. These two proteins contain extensive sequence similarities to microbial, plant and animal LPAAT sequences. LPAAT-alpha mRNA is uniformly expressed throughout most tissues with the highest level found in skeletal muscle; whereas LPAAT-beta is differentially expressed, with the highest level found in heart and liver, and negligible level in brain and placenta. The LPAAT-alpha gene is located on chromosome 6p21.3, an area within the class III region of the major hiscompatibility complex (MHC) and the LPAAT-beta gene is mapped to chromosome 9q34.3. Enhanced transcription of LPAAT-beta is suggested for neoplasm of the female genital tract. Additionally, ectopic LPAAT expression in certain cytokine-responsive cell lines can effect amplification of cellular signaling processes, such as those leading to enhancement of synthesis of tumor necrosis factor-alpha and interleukin-6 from cells following stimulation with interleukin-1beta; this suggests that the LPAAT genes represent candidates for affecting the development of certain cancers or inflammation-associated diseases.
溶血磷脂酸（LPA）和磷脂酸（PA）是两种参与细胞信号转导和脂质生物合成的磷脂。LPA酰基转移酶（LPAAT），也称为1-酰基-sn-甘油-3-磷酸酰基转移酶（1-AGPAT）（EC 2.3.1.51），催化LPA向PA的转化。LPAAT的两种人类同工型，分别命名为LPAAT-α（AGPAT1）和LPAAT-β（AGPAT2），已得到广泛研究。这两种蛋白质与微生物、植物和动物的LPAAT序列具有广泛的序列相似性。LPAAT-α mRNA在大多数组织中均一表达，在骨骼肌中表达水平最高；而LPAAT-β则呈差异表达，在心脏和肝脏中表达水平最高，在脑和胎盘中表达水平可忽略不计。LPAAT-α基因位于6号染色体p21.3上，该区域位于主要组织相容性复合体（MHC）的III类区域内，而LPAAT-β基因定位于9号染色体q34.3上。女性生殖道肿瘤中LPAAT-β的转录增强。此外，在某些细胞因子反应性细胞系中异位表达LPAAT可影响细胞信号转导过程的放大，例如在用白细胞介素-1β刺激后导致细胞合成肿瘤坏死因子-α和白细胞介素-6增强的那些过程；这表明LPAAT基因是影响某些癌症或炎症相关疾病发展的候选基因。
