A nonhistone protein that binds to heterochromatin and to the telomeres of Drosophila polytene chromosomes. It is a highly conserved protein with homologs in yeast, plants, and mammals. HP1 is required for the proper segregation of chromosomes during mitosis in embryos. It can enter nuclei and bind to specific chromosomal sites where it causes localized condensation of DNA and represses the transcriptional activity of neighboring genes. The gene Suppressor of variegation 205 encodes HP1. It is located on the left arm of chromosome 2 at 31.1. Loss of function mutant alleles are recessive lethals and cause end-to-end fusions of telomeres. Reduced function alleles cause variegation. See Chronology, 1986, James and Elgin.
Subjects: Genetics and Genomics.