Howell M. Roberts

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SWI/SNF (SWItch/sucrose non-fermentable) complexes are ATP-dependent chromatin remodeling enzymes critically involved in the regulation of multiple functions, including gene expression, differentiation, development, DNA repair, cell adhesion and cell cycle control. BRM, a key SWI/SNF complex subunit, is silenced in 15-20% of many solid tumors. As(More)
Both respiratory-competent and respiratory-deficient yeast cells reduce external ferricyanide. The reduction is stimulated by ethanol and inhibited by the alcohol dehydrogenase inhibitor, pyrazole. The reduction of ferricyanide is not inhibited by inhibitors of mitochondrial or microsomal ferricyanide reduction. Cells in exponential-phase growth show a much(More)
Hemophilia Bm, a variant of hemophilia B, results in a marked increase in the ox brain prothrombin time. Mutations known to cause hemophilia Bm occur at residue 180, 181, or 182 near the amino terminus of the heavy chain and at residue 311, 364, 368, 390, 396, or 397 near the activation site of factor IX (Giannelli et al., 1990). In this study we replaced(More)
1. Two oligomycin-resistant strains of Saccharomyces cerevisiae have been isolated and shown to have mutations in the oli2 region of the mitochondrial DNA. On solid media containing a non-fermentable energy source, the mutant strains were able to grow only slowly at 28 degrees C and not at all at 18 degrees C or 36 degrees C. 2. When grown in a(More)
An alkaline peptidase of Trypanosoma cruzi and Crithidia fasciculata, previously shown to cleave on the carboxyl side of arginine and lysine residues, was examined for its ability to cleave various fluorogenic substrates and for its sensitive to peptidase inhibitors. The enzyme of both T. cruzi and C. fasciculata has a preference for cleavage of substrates(More)
Detergent extracts of Trypanosoma cruzi epimastigotes catalysed the hydrolysis of a range of amino-acyl and peptidyl p-nitro-anilides and aminomethylcoumarins. At least three enzymes were detected that cleave Z-Phe-Arg-MCA. Two of these were optimally active at alkaline pH, the other at pH 4.0. Of the two enzymes with alkaline pH optima, one was a cysteine(More)