title: Roles of Piwi proteins in transcriptional regulation mediated by HP1s in cultured silkworm cells.
abstract: Piwi proteins are part of a superfamily of Argonaute proteins, which are one of the core components of the RNA silencing pathway in many eukaryotes. Piwi proteins are thought to repress the transposon expression both transcriptionally and post-transcriptionally. Recently, Drosophila melanogaster Piwi was recently reported to associate with chromatin and to interact directly with the Heterochromatin Protein 1 (HP1a). However, similar interactions have not been reported in other higher eukaryotes. Here we show that silkworm Piwi proteins interact with HP1s in the nucleus. The silkworm, Bombyx mori, has two Piwi proteins, Ago3 and Siwi, and two typical HP1 proteins, HP1a and HP1b. We found that HP1a plays an important role in the interaction between Ago3/Siwi and HP1b in the ovary-derived BmN4 cell line. We also found that Ago3/Siwi regulates the transcription in an HP1-dependent manner. These results suggest that silkworm Piwi proteins function as a chromatin regulator in collaboration with HP1a and HP1b.
authors.affiliation: Laboratory of Silkworm Science, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan.
authors.forename: Tsuneyuki
authors.initials: T
authors.lastname: Tatsuke
authors.affiliation: Laboratory of Silkworm Science, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan.
authors.forename: Li
authors.initials: L
authors.lastname: Zhu
authors.affiliation: Laboratory of Silkworm Science, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan.
authors.forename: Zhiqing
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mitsunobu
authors.affiliation: Laboratory of Silkworm Science, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan.
authors.forename: Kaito
authors.initials: K
authors.lastname: Yoshimura
authors.affiliation: Laboratory of Silkworm Science, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mon
authors.affiliation: Laboratory of Silkworm Science, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan.
authors.forename: Jae Man
authors.initials: JM
authors.lastname: Lee
authors.affiliation: Laboratory of Silkworm Science, Kyushu University Graduate School of Bioresource and Bioenvironmental Sciences, Fukuoka, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Kusakabe
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000378:metabolism*; D012831:Bombyx / Q000166:cytology* / Q000235:genetics*; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D005786:Gene Expression Regulation; D055785:Gene Knockdown Techniques; D019476:Insect Proteins / Q000378:metabolism*; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D060565:Argonaute Proteins; D002868:Chromosomal Proteins, Non-Histone; D019476:Insect Proteins; D012097:Repressor Proteins; D000090266:Chromobox Protein Homolog 5