Sodium orthovanadate-resistant mutants of Saccharomyces cerevisiae show defects in Golgi-mediated protein glycosylation, sporulation and detergent resistance.

Orthovanadate is a small toxic molecule that competes with the biologically important oxyanion orthophosphate. Orthovanadate resistance arises spontaneously in Saccharomyces cerevisiae haploid cells by mutation in a number of genes. Mutations selected at 3 nM sodium orthovanadate have different degrees of vanadate resistance, hygromycin sensitivity, detergent sensitivity and sporulation defects.

Vanadate-resistant mutants of Saccharomyces cerevisiae show alterations in protein phosphorylation and growth control.

This work describes two spontaneous vanadate-resistant mutants of Saccharomyces cerevisiae with constitutive alterations in protein phosphorylation, growth control, and sporulation. Vanadate has been shown by a number of studies to be an efficient competitor of phosphate in biochemical reactions, especially those that involve phosphoproteins as intermediates or substrates. Resistance to toxic concentrations of vanadate can arise in S.

A dominant trifluoperazine resistance gene from Saccharomyces cerevisiae has homology with F0F1 ATP synthase and confers calcium-sensitive growth.

The antipsychotic drug trifluoperazine has been long considered a calmodulin inhibitor from in vitro studies but may function in vivo as a more general inhibitor by disturbing ion fluxes and altering the membrane potential. Resistance to trifluoperazine can arise in Saccharomyces cerevisiae cells by alterations in at least three distinct genetic loci. One locus, defined by a spontaneous dominant trifluoperazine resistance mutation (TFP1-408), was isolated and sequenced.

Glyceraldehyde-3-phosphate dehydrogenase from Drosophila melanogaster. Identification of two isozymic forms encoded by separate genes.

The enzyme glyceraldehyde-3-phosphate dehydrogenase from Drosophila melanogaster has been purified, and these preparations contain two subunits forms which have molecular weights of 37,000 and 35,500, respectively. Each subunit is found in crude extracts, and two activity bands are seen in nondenaturing acrylamide gels. Translation of Drosophila poly(A)-containing RNA results in two products which are precipitable with anti-glyceraldehyde-3-phosphate dehydrogenase serum.

Stimulation of the Na/K pump in LK sheep erythrocytes by immunoglobulin fragments.

Alloimmune antiserum against the L antigen of red cells from sheep of the LK phenotype is known to stimulate by several fold active Na/K transport in LK cells. We have shown that monomeric fragments, Fab1, of anti-L, as well as dimeric fragments, F(ab1)2, stimulate transport to the same extent as intact anti-L Ig. Special care was taken to obtain pure fragments.