Human 15-lipoxygenase gene promoter: analysis and identification of DNA binding sites for IL-13-induced regulatory factors in monocytes

In order to study the transcriptional control of 15-LO expression, we have cloned and sequenced the human 15-LO promoter region. The 15-LO promoter is associated with a CpG island at the 5'-end of the gene, and sequence analysis reveals putative Sp1 and Ap2 binding site/s and absence of TATA or CAAT motifs. Transcription is initiated at one major site. Using deletion constructs, we have defined an active promoter region of 1056 bp. Gel-shift assays revealed that transcriptional factor(s) induced only in response to IL-13 treatment of human peripheral blood monocytes bind to the 15-LO promoter DNA. Two regions, DP1 (-140 to -92 bp) and DP2 (-353 to -304 bp) of the promoter were essential for transcription in HeLa cells and human peripheral monocytes. Hela nuclear extracts contained a specific nuclear factor(s) binding to 15-LO promoter DNA which are distinct from those derived from IL-13-treated human peripheral monocyte nuclear extracts. In addition, fluorescent in situ hybridization (FISH) results refined the previous localization of 15-LO to human chromosome 17p13.3.

Advances in the Human Genome Project. A review

While celebrating its fifth official birthday last year it seems that the Human Genome Project (HGP) has and will continue to yield important biochemical information to mankind. It is exhilarating to think about the transition from studying genome structure to understanding genome function. The collective actions of information dessimination, technology development for efficient and faster sequencing, high-volume sequencing and developing model organisms has led to its success sofar. Various genome-wide STS-based human maps were completed in 1995, including a genetic map, a YAC map, a RH map with, and an integrated YAC-RH genetic map. These maps provide comprehensive frameworks for positioning additional loci, with the current genetic and RH maps spanning essentially 100% of the human genome and the YAC maps covering 95%. Few genes, however, have yet been localized on these framework maps. To date the Human Genome Project has experienced gratifying success. The technology and data produced by the genome project will provide a strong stimulus to broad areas of biological research and biotechnology. However, enormous challenges remain.

Identification and mapping of a putative bombesin receptor gene on human chromosome 17q21.3+

A mouse bombesin receptor cDNA was used as a probe to screen a human P1 genomic library. Clone HBR1 was isolated and used to localize a putative human bombesin receptor gene (HBRKS) on human chromosome 17q21.3 by fluorescent in situ hybridization (FISH). HBRKS was identified and mapped by polymerase chain reaction (PCR) amplification from a Yeast artificial chromosome (YAC) contig spanning 17q21-q23. In addition, a few candidate genes were found by exon-trapping from HBR1.

Sodium chloride stress induced morphological and ultrastructural changes in Aspergillus repens

Halotolerant fungus, A. repens, showed a considerable difference in its growth rate, morphology, ultrastructural and molecular composition under NaCl stress as compared to control i.e. non-stressed condition. Light microscopic observations revealed significant differences in their mycelial thickness, their branching and septa. Transmission electron microscopic observations of both the conditions depicted significant differences in the qualitative and quantitative changes in mitochondria. Frequent pinocytotic vesiculation (vacuoles) of plasma membrane was observed in fungus under stress but no such vesiculation in control. The multivesiculate structures observed under stress with their origin from the cell membranes and subsequent release into vacuoles have not been reported in fungi under normal physiological conditions. The observations on pinocytosis are discussed in relation to ion compartmentation and salt tolerance in A. repens.