Biomedical subjects

Jörg Hoheisel

Publications and source records attributed to Jörg Hoheisel.

4 recordsLinked to original sources

PubMed2005

The transcriptomes of Trypanosoma brucei Lister 427 and TREU927 bloodstream and procyclic trypomastigotes.

We describe developmentally regulated genes in two strains of Trypanosoma brucei: the monomorphic strain Lister 427 and the pleomorphic strain TREU927. Expression patterns were obtained using an array of 24,567 genomic fragments. Probes were prepared from bloodstream-form or procyclic-form trypanosomes. Fourteen procyclic-specific and 77 bloodstream-specific signals were obtained from sequences matching variant surface glycoprotein or associated genes, and a further 17 regulated sequences were repetitive or transposable-element-related. Two hundred and eighty-six regulated spots corresponded to mRNAs from other protein-coding genes; these spots represent 191 different proteins. Regulation of 113 different genes (79 from procyclic forms, 34 from bloodstream-forms) was supported by at least two independent experiments or criteria; of these, about 60 were novel. Only two genes -- encoding HSP83 and an importin-related protein -- appeared to be regulated in the TREU927 strain only. Our results confirmed previous estimates that 2% of trypanosome genes show developmental regulation at the mRNA level.

Animals↗

PubMed2004

Human papillomavirus type 16 E6 promotes retinoblastoma protein phosphorylation and cell cycle progression.

We show that E6 proteins from benign human papillomavirus type 1 (HPV1) and oncogenic HPV16 have the ability to alter the regulation of the G(1)/S transition of the cell cycle in primary human fibroblasts. Overexpression of both viral proteins induces cellular proliferation, retinoblastoma (pRb) phosphorylation, and accumulation of products of genes that are negatively regulated by pRb, such as p16(INK4a), CDC2, E2F-1, and cyclin A. Hyperphosphorylated forms of pRb are present in E6-expressing cells even in the presence of ectopic levels of p16(INK4a). The E6 proteins strongly increased the cyclin A/cyclin-dependent kinase 2 (CDK2) activity, which is involved in pRb phosphorylation. In addition, mRNA and protein levels of the CDK2 inhibitor p21(WAF1/CIP1) were strongly down-regulated in cells expressing E6 proteins. The down-regulation of the p21(WAF1/CIP1) gene appears to be independent of p53 inactivation, since HPV1 E6 and an HPV16 E6 mutant unable to target p53 were fully competent in decreasing p21(WAF1/CIP1) levels. E6 from HPV1 and HPV16 also enabled cells to overcome the G(1) arrest imposed by oncogenic ras. Immunofluorescence staining of cells coexpressing ras and E6 from either HPV16 or HPV1 revealed that antiproliferative (p16(INK4a)) and proliferative (Ki67) markers were coexpressed in the same cells. Together, these data underline a novel activity of E6 that is not mediated by inactivation of p53.

3T3 Cells↗

PubMed2002

Strategy to sequence the genome of Corynebacterium glutamicum ATCC 13032: use of a cosmid and a bacterial artificial chromosome library.

The initial strategy of the Corynebacterium glutamicum genome project was to sequence overlapping inserts of an ordered cosmid library. High-density colony grids of approximately 28 genome equivalents were used for the identification of overlapping clones by Southern hybridization. Altogether 18 contiguous genomic segments comprising 95 overlapping cosmids were assembled. Systematic shotgun sequencing of the assembled cosmid set revealed that only 2.84 Mb (86.6%) of the C. glutamicum genome were represented by the cosmid library. To obtain a complete genome coverage, a bacterial artificial chromosome (BAC) library of the C. glutamicum chromosome was constructed in pBeloBAC11 and used for genome mapping. The BAC library consists of 3168 BACs and represents a theoretical 63-fold coverage of the C. glutamicum genome (3.28 Mb). Southern screening of 2304 BAC clones with PCR-amplified chromosomal markers and subsequent insert terminal sequencing allowed the identification of 119 BACs covering the entire chromosome of C. glutamicum. The minimal set representing a 100% genome coverage contains 44 unique BAC clones with an average overlap of 22 kb. A total of 21 BACs represented linking clones between previously sequenced cosmid contigs and provided a valuable tool for completing the genome sequence of C. glutamicum.

Chromosomes, Artificial, Bacterial↗

PubMed2002

Microarray data representation, annotation and storage.

Management and analysis of the huge amounts of data produced by microarray experiments is becoming one of the major bottlenecks in the utilization of this high-throughput technology. We describe the basic design of a microarray gene expression database to help microarray users and their informatics teams to set up their information services. We describe two data models--a simpler one called ArrayExpressB and the complete model ArrayExpressC, and discuss some implementation issues. For latest developments see http: wwwebi.ac.uk/arrayexpress

Algorithms↗