Mapping and functional characterization of the TAF11 interaction with TFIIA
MOLECULAR AND CELLULAR BIOLOGY
Authors: Robinson, MM; Yatherajam, G; Ranallo, RT; Bric, A; Paule, MR; Stargell, LA
Abstract
TFIIA interacts with TFIID via association with TATA binding protein (TBP) and TBP-associated factor 11 (TAF11). We previously identified a mutation in the small subunit of TFIIA (toa2-I27K) that is defective for interaction with TAF11. To further explore the functional link between TFIIA and TAF11, the toa2-I27K allele was utilized in a genetic screen to isolate compensatory mutants in TAFIL Analysis of these compensatory mutants revealed that the interaction between TAFII and TFILA involves two distinct regions of TAF11: the highly conserved historic fold domain and the N-terminal region. Cells expressing, a TAF11 allele defective for interaction with TFIIA exhibit conditional growth phenotypes and defects in transcription. Moreover. TAFII imparts changes to both TFIIA-DNA and TBP-DNA contacts in the context of promoter DNA. These alterations appear to enhance the formation and stabilization of the TFILA-TBP-DNA complex. Taken together, these studies provide essential information regarding the molecular organization of the TAF11-TFILA interaction and define a mechanistic role for this association in the regulation of gene expression in vivo.
Expression, tandem repeat copy number variation and stability of four macrosatellite arrays in the human genome
BMC GENOMICS
Authors: Tremblay, Deanna C.; Alexander, Graham, Jr.; Moseley, Shawn; Chadwick, Brian P.
Abstract
Background: Macrosatellites are some of the largest variable number tandem repeats in the human genome, but what role these unusual sequences perform is unknown. Their importance to human health is clearly demonstrated by the 4q35 macrosatellite D4Z4 that is associated with the onset of the muscle degenerative disease facioscapulohumeral muscular dystrophy. Nevertheless, many other macrosatellite arrays in the human genome remain poorly characterized. Results: Here we describe the organization, tandem repeat copy number variation, transmission stability and expression of four macrosatellite arrays in the human genome: the TAF11-Like array located on chromosomes 5p15.1, the SST1 arrays on 4q28.3 and 19q13.12, the PRR20 array located on chromosome 13q21.1, and the ZAV array at 9q32. All are polymorphic macrosatellite arrays that at least for TAF11-Like and SST1 show evidence of meiotic instability. With the exception of the SST1 array that is ubiquitously expressed, all are expressed at high levels in the testis and to a lesser extent in the brain. Conclusions: Our results extend the number of characterized macrosatellite arrays in the human genome and provide the foundation for formulation of hypotheses to begin assessing their functional role in the human genome.