Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Minireview cung cấp cho các bạn kiến thức về ngành y đề tài: The Heterochromatin Protein 1 family. | Protein family review The Heterochromatin Protein 1 family Gwen Lomberk Lori L Wallrath and Raul Urrutia Address Gastroenterology Research Unit Saint Mary s Hospital Mayo Clinic Rochester MN 55905 USA. Department of Biochemistry University of Iowa Iowa City IA 52242 USA. Correspondence Raul Urrutia. Email Published 21 July 2006 Genome Biology 2006 7 228 doi gb-2006-7-7-228 The electronic version of this article is the complete one and can be found online at http 2006 7 7 228 2006 BioMed Central Ltd Summary Heterochromatin Protein 1 HP1 was first discovered in Drosophila as a dominant suppressor of position-effect variegation and a major component of heterochromatin. The HP1 family is evolutionarily conserved with members in fungi plants and animals but not prokaryotes and there are multiple members within the same species. The amino-terminal chromodomain binds methylated lysine 9 of histone H3 causing transcriptional repression. The highly conserved carboxy-terminal chromoshadow domain enables dimerization and also serves as a docking site for proteins involved in a wide variety of nuclear functions from transcription to nuclear architecture. In addition to heterochromatin packaging it is becoming increasingly clear that HP1 proteins have diverse roles in the nucleus including the regulation of euchromatic genes. HP1 proteins are amenable to posttranslational modifications that probably regulate these distinct functions thereby creating a subcode within the context of the histone code of histone posttranslational modifications. Gene organization and evolutionary history Heterochromatin protein 1 HP1 was originally discovered through studies in Drosophila of the mosaic gene silencing that results when a euchromatic gene is placed near or within heterochromatin the condensed state of chromatin that is a cytologically visible condition of heritable gene repression 1 2 . This phenomenon is known as positioneffect .
