Open AccessActivation and repression sequences determine the lens-specific expression of the ratγD-crystallin gene
Author(s) -
Ron Peek,
H Kraft,
Erik Jan Klok,
Nicolette H. Lubsen,
John G.G. Schoenmakers
Publication year - 1992
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/20.18.4865
Subject(s) - biology , crystallin , enhancer , gene silencing , microbiology and biotechnology , psychological repression , lens (geology) , regulatory sequence , gene , silencer , promoter , gene expression , genetics , mechanical engineering , paleontology , engineering , inlet
Rat lens nuclear extracts contain a factor that binds to position -57 to -46 of the rat gamma D-crystallin promoter region. This factor protects the sequence 5'-CTGCCAACGCAG-3' in a footprint analysis. Binding to this region is crucial for maximal promoter activity in rat lens cells, but this sequence was unable to act as an enhancer when cloned in front of a heterologous promoter. A region directly upstream from this activating sequence, between position -85 to -67, acts as a strong silencer of promoter activity in non-lens cells. This silencing effect is mediated by trans-acting factor(s). Our data provide evidence for two regulatory elements in rat gamma D-crystallin gene expression, an activating sequence active in lens cells and a silencing sequence active only in non-lens cells. The factor that binds to the activating sequence could be detected only in lens cells and may be a determinant of the lens-specific expression of the gamma-crystallin genes.