Scott Bruce T, Olson Nels, Long George L, Bovill Edwin G
Department of Pathology, University of Vermont, Burlington, VT, USA.
Prostaglandins Other Lipid Mediat. 2008 Mar;85(3-4):69-80. doi: 10.1016/j.prostaglandins.2007.10.005. Epub 2007 Nov 9.
Platelet activating factor acetylhydrolase (paf-ah), a potent regulator of platelet activating factor activity, plays an important role in various physiological and pathophysiological functions including development, reproduction, inflammation, hemostasis, and apoptosis. Intracellular paf-ah (paf-ah-Ib) is composed of a regulatory subunit, Pafah1b1, and two highly conserved but non-identical catalytic subunits, Pafah1b2 and Pafah1b3. The present study identifies new splice variants of the Pafah1b2 gene transcript. The splice variants retain exons 1-5 and replace exon 6 with alternative exons derived from genomic sequence 3' to exon 6. Splice variants encode two proteins with different novel carboxy termini. One of the isoforms is expressed exclusively in testis. These new isoforms of pafah1b2 retain the ability to form higher order complexes while replacing known key catalytic residues, which raises the possibility that they may alter the subunit composition and catalytic function of paf-ah-Ib.
血小板活化因子乙酰水解酶（PAF-AH）是血小板活化因子活性的强效调节剂，在包括发育、生殖、炎症、止血和凋亡在内的各种生理和病理生理功能中发挥重要作用。细胞内PAF-AH（PAF-AH-Ib）由一个调节亚基Pafah1b1和两个高度保守但不完全相同的催化亚基Pafah1b2和Pafah1b3组成。本研究鉴定了Pafah1b2基因转录本的新剪接变体。这些剪接变体保留了外显子1-5，并用源自外显子6 3'端基因组序列的替代外显子替换了外显子6。剪接变体编码两种具有不同新型羧基末端的蛋白质。其中一种异构体仅在睾丸中表达。Pafah1b2的这些新异构体在替换已知关键催化残基的同时保留了形成高阶复合物的能力，这增加了它们可能改变PAF-AH-Ib亚基组成和催化功能的可能性。
