Association of yeast SAP1, a novel member of the 'AAA' ATPase family of proteins, with the chromatin protein SIN1.
The yeast SIN1 protein is a nuclear protein that together with other proteins behaves as a transcriptional repressor of a family of genes. In addition, sin1 mutants are defective in proper mitotic chromosome segregation. In an effort to understand the basis for these phenotypes, we employed the yeast two-hybrid system to identify proteins that interact with SIN1 in vivo. Here, we demonstrate that SAP1, a novel protein belonging to the 'AAA' family of ATPases, is able to directly interact with SIN1. Furthermore, we show, using recombinant molecules in vitro, that a short 27 amino acid sequence near the N-terminal of SIN1 is sufficient to bind SAP1. Previous experiments defined different domains of SIN that interact with other proteins and with DNA. The C-terminal domain of SIN1 was shown to be responsible for interaction with a protein that binds the regulatory region of HO, a gene whose transcription is repressed by SIN1. The central 'HMG1-like region' of SIN1 binds DNA, while the N-terminal of SIN1 can bind CDC23, a protein that regulates chromosome segregation. These data, taken together with the results presented here, suggest that SIN1 is a multifunctional chromatin protein that can interact with a number of different proteins that are involved in several different cellular functions.
Liberzon
A
A
Department of Life Sciences, Bar Ilan University, Ramat Gan, Israel.
Shpungin
S
S
Bangio
H
H
Yona
E
E
Katcoff
D J
DJ
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001483:Base Sequence; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics; D008969:Molecular Sequence Data; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; C099837:SAP1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C069938:SPT2 protein, S cerevisiae; D005982:Glutathione Transferase; D000251:Adenosine Triphosphatases