Biomedical subjects
Publications and source records attributed to N Groot.
In last few years much data has accumulated on various non-translatable RNA transcripts that are synthesised in different cells. They are lacking in protein coding capacity and it seems that they work mainly or exclusively at the RNA level. All known non-coding RNA transcripts are collected in the database: http://www. man.poznan.pl/5SData/ncRNA/index.html
The enzyme cytidylyl cyclase catalyses the conversion of cytidine 5'-triphosphate into cytidine 3',5'-cyclic monophosphate, a third naturally occurring cyclic nucleotide currently under investigation to assign a biochemical function. Quantitation of the activity of this enzyme has been carried out by the positive-ion fast-atom bombardment mass spectrometric analysis of the enzyme incubation mixture after the reaction has been terminated. The data obtained are in good agreement with those obtained from the conventional radiometric and radioimmunoassays of the same enzyme preparations. The advantage of the mass spectrometer-based assay is the facility for multiple component monitoring. Thus, the production of the cytidine diphosphates and monophosphates, and the production of four cytidine 3',5'-cyclic monophosphate analogues as side-products, were simultaneously estimated. The identities of two of the side-products, 2'-O-glutamyl- and 2'-O-aspartyl-cytidine-3',5'-cyclic monophosphate, and of the cytidine 3',5'-cyclic monophosphate product, were confirmed by mass-analysed ion kinetic energy spectra from the collision-induced dissociation of the protonated molecules.
We have previously used exon amplification to identify the ADD1 gene in cosmid Y24 from the Huntington's disease (HD) region of 4p16.3. The same technique has now yielded a second gene from this cosmid. This gene appears to encode a novel member of a superfamily of transporter proteins that includes active and passive transporters in a number of species. The predicted protein of 455 amino acids displays sequence similarity with the E. coli tetracycline resistance efflux protein encoded by cloning vector pBR322, and with a number of related transporters. This gene should open a route to isolating additional mammalian members of this growing superfamily.
The generation of sequence-tagged sites (STSs) has been proposed as a unifying approach to correlating the disparate results generated by genetic and various physical techniques being used to map the human genome. We have developed an STS map to complement the existing physical and genetic maps of 4p16.3, the region containing the Huntington disease gene. A total of 18 STSs span over 4 Mb of 4p16.3, with an average spacing of about 250 kb. Eleven of the STSs are located within the primary candidate HD region of 2.5 Mb between D4S126 and D4S168. The availability of STSs makes the corresponding loci accessibility to the general community without the need for distribution of cloned DNA. These STSs should also provide the means to isolate yeast artificial chromosome clones spanning the HD candidate region.
We have applied the technique of exon amplification to the isolation of genes from the chromosome 4p16.3 Huntington's disease (HD) candidate region. Exons recovered from cosmid Y24 identified cDNA clones corresponding to the alpha-subunit of adducin, a calmodulin-binding protein that is thought to promote assembly of spectrin-actin complexes in the formation of the membrane cytoskeleton, alpha-adducin is widely expressed and, at least in brain, is encoded by alternatively spliced mRNAs. The alpha-adducin gene maps immediately telomeric to D4S95, in a region likely to contain the HD defect, and must be scrutinized to establish whether it is the site of the HD mutation.
Within the Huntington's disease (HD) candidate region of 4p16.3, the D4S127 locus displays strong linkage disequilibrium with the defect and anchors a conserved haplotype found on many HD chromosomes. To isolate genes from this region we have applied the exon amplification technique to overlapping cosmids spanning D4S127. Here, we report the discovery of a new gene encoding a novel member of a family of protein kinases that specifically phosphorylate the activated forms of G protein-coupled receptors. Such kinases are thought to participate in desensitization of specific receptors, thereby blocking further signal transduction. This gene must now be carefully scrutinized to determine whether it might be involved in HD.