title: GPAT2, a mitochondrial outer membrane protein, in piRNA biogenesis in germline stem cells.
abstract: piRNA (PIWI-interacting RNA) is a germ cell-specific small RNA in which biogenesis PIWI (P-element wimpy testis) family proteins play crucial roles. MILI (mouse Piwi-like), one of the three mouse PIWI family members, is indispensable for piRNA production, DNA methylation of retrotransposons presumably through the piRNA, and spermatogenesis. The biogenesis of piRNA has been divided into primary and secondary processing pathways; in both of these MILI is involved in mice. To analyze the molecular function of MILI in piRNA biogenesis, we utilized germline stem (GS) cells, which are derived from testicular stem cells and possess a spermatogonial phenotype. We established MILI-null GS cell lines and their revertant, MILI-rescued GS cells, by introducing the Mili gene with Sendai virus vector. Comparison of wild-type, MILI-null, and MILI-rescued GS cells revealed that GS cells were quite useful for analyzing the molecular mechanisms of piRNA production, especially the primary processing pathway. We found that glycerol-3-phosphate acyltransferase 2 (GPAT2), a mitochondrial outer membrane protein for lysophosphatidic acid, bound to MILI using the cells and that gene knockdown of GPAT2 brought about impaired piRNA production in GS cells. GPAT2 is not only one of the MILI bound proteins but also a protein essential for primary piRNA biogenesis.
authors.affiliation: Department of Pathology, Medical School, 2Graduate School of Frontier Biosciences, Osaka University, Yamada-oka 2-2 Suita, Osaka 565-0871, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Shiromoto
authors.forename: Satomi
authors.initials: S
authors.lastname: Kuramochi-Miyagawa
authors.forename: Akito
authors.initials: A
authors.lastname: Daiba
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Chuma
authors.forename: Ami
authors.initials: A
authors.lastname: Katanaya
authors.forename: Akiko
authors.initials: A
authors.lastname: Katsumata
authors.forename: Ken
authors.initials: K
authors.lastname: Nishimura
authors.forename: Manami
authors.initials: M
authors.lastname: Ohtaka
authors.forename: Mahito
authors.initials: M
authors.lastname: Nakanishi
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Nakamura
authors.forename: Koichi
authors.initials: K
authors.lastname: Yoshinaga
authors.forename: Noriko
authors.initials: N
authors.lastname: Asada
authors.forename: Shota
authors.initials: S
authors.lastname: Nakamura
authors.forename: Teruo
authors.initials: T
authors.lastname: Yasunaga
authors.forename: Kanako
authors.initials: K
authors.lastname: Kojima-Kita
authors.forename: Daisuke
authors.initials: D
authors.lastname: Itou
authors.forename: Tohru
authors.initials: T
authors.lastname: Kimura
authors.forename: Toru
authors.initials: T
authors.lastname: Nakano
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism; D015153:Blotting, Western; D018797:Cell Cycle Proteins; D002478:Cells, Cultured; D055785:Gene Knockdown Techniques; D005822:Genetic Vectors / Q000378:metabolism; D005992:Glycerol-3-Phosphate O-Acyltransferase / Q000235:genetics / Q000378:metabolism*; D047468:Immunoprecipitation; D008246:Lysophospholipids / Q000378:metabolism; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000378:metabolism; D011485:Protein Binding; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D017411:Ribonucleoproteins, Small Nuclear / Q000235:genetics / Q000378:metabolism; D029082:Sendai virus / Q000235:genetics / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D013737:Testis / Q000166:cytology / Q000378:metabolism*
chemical_list: D060565:Argonaute Proteins; D018797:Cell Cycle Proteins; D008246:Lysophospholipids; D035683:MicroRNAs; C448521:Piwil2 protein, mouse; D034741:RNA, Small Interfering; D017411:Ribonucleoproteins, Small Nuclear; C488681:Tdrd1 protein, mouse; D005992:Glycerol-3-Phosphate O-Acyltransferase; C571223:glycerol-3-phosphate acyltransferase 2, mouse; C032881:lysophosphatidic acid
keywords: GPAT2; GS cells; MILI; mitochondria; piRNA