High impact information on MOT1

• Basal transcription of many genes in yeast is repressed by Mot1, an essential protein which is a member of the Snf2/Swi2 family of conserved nuclear factors [1].
• Recombinant Mot1 removes TBP from DNA and Mot1 contains an ATPase activity which is essential for its function [1].
• In contrast, levels of Taf1, TFIIB, and RNA polymerase II are reduced at Mot1-activated promoters in mot1 cells [2].
• In vitro, Mot1 utilizes ATP hydrolysis to disrupt TBP-DNA complexes, but the relationship of this activity to Mot1's in vivo function is unclear [2].
• Interestingly enough, Spt3 and Mot1 were recruited on the GAL1 promoter as well as on the nonpromoter site in an interdependent manner [3].

Biological context of MOT1

• Construction of a null allele confirmed that MOT1 is an essential gene [4].
• MOT1 residues on chromosome XVI and encodes a large protein of 1,867 amino acids which contains all seven of the conserved domains found in known and putative helicases [4].
• A presumptive helicase (MOT1 gene product) affects gene expression and is required for viability in the yeast Saccharomyces cerevisiae [4].
• In addition, mot1 mutants have other phenotypes in common with spt3 delta mutants, including suppression of the insertion mutation his4-912 delta [5].
• Differential requirement of SAGA subunits for Mot1p and Taf1p recruitment in gene activation [6].

Anatomical context of MOT1

• Native Mot1 and derivatives deleterious to growth localized in the nucleus, whereas nontoxic derivatives localized to the cytosol, suggesting TBP binding and nuclear transport of Mot1 are coupled [7].
• The homology of 89B Helicase to Mot1, its widespread developmental expression and its large number of targets on the polytene chromosomes of larval salivary gland cells suggest that 89B Helicase may play a role in chromosomal metabolism, particularly global transcriptional regulation [8].

Associations of MOT1 with chemical compounds

• Among the genes we cloned is MOT1, encoding a repressor that inhibits TBP binding to the promoter, thus linking glucose repression with TBP access to chromatin [9].

Physical interactions of MOT1

• Evidence that Spt3 functionally interacts with Mot1, TFIIA, and TATA-binding protein to confer promoter-specific transcriptional control in Saccharomyces cerevisiae [5].
• MOT1 encodes an essential ATPase that functions as a general transcriptional regulator in vivo by modulating TATA-binding protein (TBP) DNA-binding activity [10].
• These results suggest that Mot1-mediated dissociation of TBP (or TBP-containing complexes) from chromatin can explain the Mot1 activation mechanism at some promoters [11].

Regulatory relationships of MOT1

• ATPase assays demonstrate that the MOT1 ATPase is activated by TBP [12].
• The growth defect of a not5 mutant can be suppressed by a mot1 mutant [13].

Other interactions of MOT1

• The molecular cloning and characterization of BUR3 and BUR6 are presented here [14].
• Second, in contrast to not mutations, mutations in MOT1 decreased HIS3 and HIS4 TATA-less transcription [15].
• RAD54 exhibits homologies to several known ATPases and is a member of the SWI2/MOT1 family [16].
• BUR3 is identical to MOT1, a previously characterized essential gene that encodes an ATP-dependent inhibitor of the TATA box-binding protein [14].
• Genetic interactions between Nhp6 and Gcn5 with Mot1 and the Ccr4-Not complex that regulate binding of TATA-binding protein in Saccharomyces cerevisiae [13].
• The results suggest that Mot1-mediated activation of URA1 transcription involves at least two steps, one of which is the removal of TBP bound to the promoter in the opposite orientation required for URA1 transcription [17].

Analytical, diagnostic and therapeutic context of MOT1

• Although MOT1 was originally identified both biochemically and in several genetic screens as a transcriptional repressor, a combination of subsequent genetic, chromatin immunoprecipitation, and microarray analysis suggested that MOT1 might also have an additional role in vivo as a transcriptional activator [10].
• Chromatin immunoprecipitation was used to determine how Mot1 affects the assembly of preinitiation complexes (PICs) at Mot1-controlled promoters in vivo [2].

References