Open AccessChanges in a SWI4,6-DNA-binding complex occur at the time of HO gene activation in yeast.
Author(s) -
Maria Rita Miyagusko Taba,
Ivor Muroff,
David Lydall,
Graham Tebb,
Kim Nasmyth
Publication year - 1991
Publication title -
genes and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.136
H-Index - 438
eISSN - 1549-5477
pISSN - 0890-9369
DOI - 10.1101/gad.5.11.2000
Subject(s) - biology , gene , dna binding protein , cytoplasm , yeast , transcription factor , transcription (linguistics) , dna , microbiology and biotechnology , electrophoretic mobility shift assay , genetics , linguistics , philosophy
The yeast HO gene is transcribed transiently during G1 as cells undergo START. START-specific HO activation requires two proteins, SWI4 and SWI6, which act via a motif (CACGA4) repeated up to 10 times within the URS2 region of the HO promoter. We identified a DNA-binding activity containing SWI4 and SWI6 that recognizes the CACGA4 sequences within URS2. Two forms of SWI4,6-DNA complexes called L and U can be distinguished by their electrophoretic mobility. L complexes can be detected at all stages of the cell cycle, but U complexes are only detected in cells that have undergone START. The formation of U complexes may be the trigger of HO activation. The SWI6 protein is concentrated in the nucleus throughout G1, but at some point in S or G2 significant amounts accumulate in the cytoplasm. This change in cellular location of the SWI6 protein might contribute to the turnoff of HO transcription after cells have undergone START.