The primary structure of nucleoside diphosphate (NDP) kinase II, one of the two isozymes found in spinach leaves, has been deduced from its cDNA sequence. NDP kinase II comprises 233 amino acid residues and has a molecular mass of 26,107 Da, which is larger than that of the purified NDP kinase II subunits (18 kDa) by about 8 kDa, suggesting that NDP kinase II might be post-translationally processed. Homology was found between the sequence of spinach NDP kinase II, and the sequences of spinach NDP kinase I, rat NDP kinases alpha and beta, Dictyostelium discoideum NDP kinase, the human Nm23-H1 and Nm23-H2 proteins and the awd protein of Drosophila melanogaster.

Teprenone (geranylgeranylacetone) is a gastric mucosal protective drug used clinically in Japan for treatment of gastric ulcers and gastritis. Its effect on portal hypertensive (PHT) gastric mucosa which has impaired defensive mechanisms is not known. In 20 PHT and 20 sham-operated rats, we studied the effects of teprenone or placebo on: (1) portal pressure; (2) gastric pH; (3) gastric mucosal blood flow using laser doppler flowmetry, and (4) hexosamine content in gastric mucosa. The gastric mucosal blood flow was significantly higher in the PHT + teprenone group than in the PHT + placebo group (463 +/- 75 and 381 +/- 82 perfusion units, respectively; p < 0.05). The hexosamine content was significantly lower in PHT rats than in sham-operated controls (12.6 +/- 2.3 vs. 14.3 +/- 2.2 micrograms/mg, respectively). Teprenone treatment significantly increased the gastric mucosal hexosamine concentration in both sham-operated and PHT rats (17.2 +/- 3.1 and 15.6 +/- 3.6 micrograms/mg, respectively). These effects of teprenone, combined with its known prostaglandin-stimulating action, suggest a potential role for this agent in the treatment of PHT gastric mucosal abnormalities.

Drosophila taste gene Tre is located on the distal X chromosome and controls gustatory sensitivity to a subset of sugars [1, 2]. Two adjacent, seven-transmembrane domain genes near the Tre locus are candidate genes for Tre. One (CG3171) encodes a rhodopsin family G protein receptor [3, 4], and the other (Gr5a) is a member of a chemosensory gene family encoding a putative gustatory receptor [5-7]. We carried out molecular analyses of mutations in Tre to elucidate their involvement in the gustatory phenotype. Here, we show that Tre mutations induced by P element-mediated genomic deletions disrupt Gr5a gene organization and the expression of Gr5a mRNA, while disruption of the CG3171 gene or its expression was not always associated with mutations in Tre. In flies with the spontaneous mutation Tre(01), both CG3171 and Gr5a mRNAs are transcribed. Coding sequences of these two candidate genes were compared among various strains. A total of three polymorphic sites leading to amino acid changes in CG3171 were not correlated with the gustatory phenotype. Among four nonsynonymous sites in Gr5a, a single nucleotide polymorphism leading to an Ala218Thr substitution in the predicted second intracellular loop cosegregated with Tre(01). Taken together, the mutation analyses support that Gr5a is allelic to Tre.

A polymorphism in the nucleic acid sequence encoding the signal peptide of the human prepro-vasopressin (AVP) has been reported in an AVP producing small cell lung carcinoma (SCLC) cell line. The difference predicts expression in tumor cells of a variant signal peptide with Pro for Leu 11. To clarify whether this difference is required for AVP secretion from SCLC cells and/or reflects increased mutagenesis in malignant tumors, the exon encoding the signal peptide of prepro-AVP in two AVP producing SCLC and 9 non-producing lung tumors was amplified using polymerase chain reaction. The variant sequence was neither found by direct sequencing nor by restriction enzyme analysis. These results suggest that similar to the hypothalamus the normal signal peptide is functional in tumor cells and that the variant signal peptide is not a prerequisite for AVP secretion from SCLC cells.