Sugimoto Keiki, Kage Hidenori, Aki Naomi, Sano Atsushi, Kitagawa Hiroshi, Nagase Takahide, Yatomi Yutaka, Ohishi Nobuya, Takai Daiya
Department of Respiratory Medicine, The University of Tokyo Hospital, Tokyo, Japan.
Biochem Biophys Res Commun. 2007 Aug 3;359(3):497-502. doi: 10.1016/j.bbrc.2007.05.136. Epub 2007 May 29.
The field of epigenetics has made progress by the identification of the small RNA-mediated epigenetic modification. However, little is known about the key proteins. Here, we report that the human PIWI-like family is a candidate protein that is involved in the pathway responsible for chromatin remodeling. The PIWI-like family proteins, expressed as the Flag-fusion proteins, formed a bulky body and localized to the nuclear periphery. Transient transfection of PIWI-like 4 (PIWIL4), only member of the PIWI-like family that was ubiquitously expressed in human tissues, induced histone H3 lysine 9 methylation at the p16(Ink4a) (CDKN2A) locus. The elevated level of histone methylation resulted in the downregulation of the p16(Ink4a) gene. These results suggest PIWIL4 plays important roles in the chromatin-modifying pathway in human somatic cells.
