The Schizosaccharomyces pombe spqM gene is a new member of the Qm transcription factor family

Current awareness on yeast

In order to keep subscribers up-to-date with the latest developments in their field, this current awareness service is provided by John Wiley & Sons and contains newly-published material on yeasts. Each bibliography is divided into 10 sections. 1 Books, Reviews & Symposia; 2 General; 3 Biochemistry; 4 Biotechnology; 5 Cell Biology; 6 Gene Expression; 7 Genetics; 8 Physiology; 9 Medical Mycology; 10 Recombinant DNA Technology. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted. (5 weeks journals - search completed 31st May 2000)

Tissue-/stage-dependent expression of a cloned Bombyx mandarina QM homologue

QM, a novel gene that was firstly isolated as a putative tumor suppressor gene from Wilms' tumor cell line. Although it is well known that the QM gene product plays an important role within the tumor cells, the precise role of QM in the non-tumor cells has remained elusive. With in this mind we isolated a cDNA encoding QM homologue from Bombyx mandarina to understand the function of QM. The 596 bp cDNA has an open reading frame of 219 amino acids and a predicted mol. wt. of 25 kDa. The protein has more than 88% amino acid sequence identity to the QM protein from Drosophila melanogaster. mRNA expression gradually increased from 1-2 days after egg laying to 2 days of finial instar, while very low expressions were detected for either the pupae and the moth stages. The organs, posterior/middle division of silkgland, midgut, fat body and malpighian tubes, also show relatively high mRNA expression levels, respectively. The high degree of conservation and expression of the B. mandarina QM homologous suggest that it has a selectively conserved amino acid sequence due, presumably, to an important biological role which is associated with pupae formation.

Schizosaccharomyces pombe apn1 encodes a homologue of the Escherichia coli endonuclease IV family of DNA repair proteins

The Apn1 protein of the budding yeast Saccharomyces cerevisiae is a DNA repair enzyme that hydrolyzes apurinic/apyrimidinic (AP) sites and removes 3'-blocking groups present at single strand breaks of damaged DNA. Yeast cells lacking Apn1 are hypersensitive to DNA damaging agents that produce AP sites and DNA strand breaks with blocked 3'-termini. In this study, we showed that the fission yeast Schizosaccharomyces pombe bears a homologue, Spapn1, that is 45% identical to S. cerevisiae Apn1. However, the Spapn1 gene is apparently not expressed. Active expression of S. cerevisiae Apn1 in S. pombe conferred no additional resistance to DNA damaging agents. These data suggest that the pathway by which S. pombe repairs AP sites is independent of a functional Apn1-like AP endonuclease.