Altering mammalian transcription networking with ADAADi: An inhibitor of ATP-dependent chromatin remodeling.

Active DNA-dependent ATPase A Domain inhibitor (ADAADi) is the only known inhibitor of ATP-dependent chromatin remodeling proteins that targets the ATPase domain of these proteins. The molecule is synthesized by aminoglycoside phosphotransferase enzyme in the presence of aminoglycosides. ADAADi interacts with ATP-dependent chromatin remodeling proteins through motif Ia present in the conserved helicase domain, and thus, can potentially inhibit all members of this family of proteins.

BRG1 is a prognostic indicator and a potential therapeutic target for prostate cancer.

Brahma-related gene 1 (BRG1) is one of two mutually exclusive ATPases that function as the catalytic subunit of human SWItch/Sucrose NonFermentable (SWI/SNF) chromatin remodeling enzymes. BRG1 has been identified as a tumor suppressor in some cancer types but has been shown to be expressed at elevated levels, relative to normal tissue, in other cancers. Using TCGA (The Cancer Genome Atlas) prostate cancer database, we determined that BRG1 mRNA and protein expression is elevated in prostate tumors relative to normal prostate tissue.

Global epigenetic changes induced by SWI2/SNF2 inhibitors characterize neomycin-resistant mammalian cells.

Background: Previously, we showed that aminoglycoside phosphotransferases catalyze the formation of a specific inhibitor of the SWI2/SNF2 proteins. Aminoglycoside phosphotransferases, for example neomycin-resistant genes, are used extensively as selection markers in mammalian transfections as well as in transgenic studies. However, introduction of the neomycin-resistant gene is fraught with variability in gene expression.

Elucidating the mechanism of DNA-dependent ATP hydrolysis mediated by DNA-dependent ATPase A, a member of the SWI2/SNF2 protein family.

The active DNA-dependent ATPase A domain (ADAAD), a member of the SWI2/SNF2 family, has been shown to bind DNA in a structure-specific manner, recognizing DNA molecules possessing double-stranded to single-stranded transition regions leading to ATP hydrolysis. Extending these studies we have delineated the structural requirements of the DNA effector for ADAAD and have shown that the single-stranded and double-stranded regions both contribute to binding affinity while the double-stranded region additionally plays a role in determining the rate of ATP hydrolysis. We have also investigated the mechanism of interaction of DNA and ATP with ADAAD and shown that each can interact independently with ADAAD in the absence of the other.

Involvement of a Na+/HCO-3 cotransporter in mouse sperm capacitation.

Mammalian sperm are incapable of fertilizing eggs immediately after ejaculation; they acquire fertilization capacity after residing in the female tract for a finite period of time. The physiological changes sperm undergo in the female reproductive tract that render sperm able to fertilize constitute the phenomenon of "sperm capacitation." We have demonstrated that capacitation is associated with an increase in the tyrosine phosphorylation of a subset of proteins and that these events are regulated by an HCO(3)(-)/cAMP-dependent pathway involving protein kinase A.

Context-dependent roles of the Entamoeba histolytica core promoter element GAAC in transcriptional activation and protein complex assembly.

Transcriptional control of the hgl5 gene of Entamoeba histolytica is mediated through an unusual core promoter composed of TATA, GAAC and Initiator elements. In the hgl5 promoter the GAAC element (AATGAACT) determines the site and rate of transcription initiation. Here we tested the role of the GAAC element in transcription activation from upstream regulatory elements (UREs) in the hgl5 promoter.