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Biomedical subjects

B Brenig

Publications and source records attributed to B Brenig.

At least 91 records · Page 5Linked to original sources
PubMed1999

Isolation and characterization of the porcine c-myc proto-oncogene and chromosomal assignment to SSC 4p13.

The proto-oncogene c-myc codes for a nuclear phosphoprotein, a transcription factor composed of the typical basic/helix-loop-helix/leucine zipper domains. Its expression is coupled to a multitude of physiological processes and regulated by a variety of hormones, growth factors, cytokines, lymphokines and the nutritional status, development and differentiation. Its key roles have been characterized, e.g. in adipogenesis, myogenesis and folliculogenesis. We have isolated and sequenced a 6.4-kb genomic fragment encoding the porcine c-myc proto-oncogene. The gene shows the typical c-myc structure with three exons, three putative promoters and a deduced protein of 439 amino acids. The porcine c-myc was mapped to chromosome 4p13 by screening of a porcine-rodent hybrid cell panel.

Animals↗
PubMed1999

Conserved nucleotide differences and subfamily structure of porcine short interspersed elements.

Interspersed elements are ubiquitous in the genomes of higher eukaryotes and account for over a third of the genomic DNA (Smit 1996). In swine the short interspersed elements, SINEs or PREs (porcine repetitive elements), have been found in a number of introns and 3' untranslated regions of different genes. However, compared to human Alu repeats the number of available PRE DNA sequences is still limited. In this study we have compared 85 PREs selected from DNA sequence database entries. The PREs were aligned and for each nucleotide position the relative frequencies of the four bases were calculated. A consensus sequence was derived from the first base usage. Similar to studies of SINEs in other species, the analysis showed that most mutations in PREs occur at CpG dinucleotide hot spots. The position variability for the two most frequent bases shows a bimodal distribution. The analysis suggests that the porcine SINEs can be divided into three major subfamilies sharing conserved nucleotide similarities.

Animals↗
PubMed1998

cDNA cloning and sequencing of the human ryanodine receptor type 3 (RYR3) reveals a novel alternative splice site in the RYR3 gene.

The human ryanodine receptor type 3 (RYR3) was cloned from a fetal brain cDNA library and its complete sequence was determined (EMBL accession number AJ001515). The sequenced cDNA spanned 15,564 bp and contained an open reading frame of 14,613 bp. The corresponding protein consisted of 4870 amino acids with a calculated molecular mass of 552 kDa. Amino acid sequence identities to the RYR3 proteins from rabbit, mink, and chicken were 96%, 95%, and 83% respectively. A previously unidentified alternative splice site was detected generating a transcript that lacked bases 11,569-11,650 and encoded a truncated protein.

Alternative Splicing↗
PubMed1998

Site-directed mutagenesis of boar proacrosin reveals residues involved in binding of zona pellucida glycoproteins.

Proacrosin, the zymogen form of the serine protease beta-acrosin, is thought to function as a secondary binding molecule between mammalian gametes during fertilization (Jansen et al., 1995: Int J Dev Biol 39, 501-510). The interaction involves strong ionic bonds between positively charged amino acids on proacrosin and negatively charged polysulphate groups on zona pellucida glycoproteins. In this investigation, we identified the basic residues on proacrosin that are important for this binding. Site-directed mutagenesis shows that two groups of amino acids comprising His47, Arg50, and Arg51 together with Arg250, Lys252, and Arg253 are crucial because their deletion or replacement severely reduces affinity for zona glycoproteins. Molecular models of proacrosin reveal that these residues are located along one face of the protein on two exposed surface loops that project over and around the catalytic site. These findings support the hypothesis that polysulphate binding sites on proacrosin are formed by a restricted number of basic amino acids on the surface of the protein, presenting a specific orientation that is complementary to negatively charged sulphate groups on zona glycoproteins. Identification and elucidation of the stereochemistry of these charged moieties will aid design of new kinds of nonsteroidal antifertility agents.

Acrosin↗
PubMed1998

Structural and functional analysis of the porcine secretory carrier membrane protein 1 gene (SCAMP1).

The secretory carrier membrane proteins (SCAMPs) are highly conserved integral vesicle membrane components of the post-Golgi secretory and endocytic pathways. We have isolated and characterized the porcine SCAMP1 cDNA and gene coding for a variant of the SCAMP family. The SCAMP1 cDNA has a length of 3827 bp including a 133-bp 5' and 2701-bp 3' untranslated region. The mRNA has an open reading frame of 1014 nt coding for a protein of 338 amino acids with a calculated molecular mass of 37.9 kDa and a pI of 7.9. The porcine SCAMP1 is 97.04% identical with the human and rat paralogs, respectively. The SCAMP1 gene consists of nine exons with sizes ranging from 78 to 2842 bp and spans at least 70 kb of genomic DNA on porcine Chromosome (Chr) 2q21-q22. The promoter of the SCAMP1 gene is TATA-box-less, and transcription starts at a G-nucleotide 133 nt upstream the start codon.

Amino Acid Sequence↗
PubMed1998

Cytogenetic localization of genetic markers on porcine chromosome 7q.

Four microsatellite markers (S0078, SWR1210, SW732, and SW304) taken from the linkage map of porcine chromosome 7 were assigned to the cytogenetic map of pig chromosome 7 by fluorescence in situ hybridization (FISH) analysis of selected yeast artificial chromosomes (YACs). These four new polymorphic cytogenetic markers provide additional anchor points for integrating the linkage and cytogenetic maps of chromosomal region 7q.

Animals↗
PubMed1998

Emulation of an ELISA reader and quantitative image analysis using the computer program Digital-OD.

Here, we present a Microsoft Windows application that has been written to emulate a microplate reader. After scanning a standard 96-well microplate, color gradations in the slots can be analyzed quantitatively and be used for the estimation of enzyme kinetics, binding assays or concentration determination. In a test, series accuracy of the program was determined. We show that the returned optical densities correlated highly with the true concentrations (r > 0.97). Thus, the software is useful for a wide number of applications. Further, the program is easy to handle and is available free of charge.

Enzyme-Linked Immunosorbent Assay↗
PubMed1998

Ryanodine receptors and their role in genetic diseases (review).

The skeletal muscle ryanodine receptor (RYR1) is a calcium release channel that mediates efflux of calcium ions from the sarcoplasmic reticulum into the myoplasm during excitation-contraction coupling. Mutations in the RYR1 gene have been detected in about 50% of the patients suffering from malignant hyperthermia (MH), but evidence is accumulating that other genetic defects can also lead to MH in humans. MH is a life-threatening disorder induced by exposure to volatile anesthetics and/or the muscle relaxans succinylcholin during surgical procedures in affected patients. MH leads to skeletal muscle rigidity, hypermetabolism and rapid rise in body temperature. MH is also known in pigs where it is triggered by stress and therefore often referred to as porcine stress syndrome. The existence of an animal model has greatly faciliated the elucidation of the basis for the human disease. This review describes recent advances in the understanding of the physiological action of ryanodine receptors and new insights regarding the relation between different RYR1 mutations and distinct phenotypical appearances.

Alternative Splicing↗
PubMed1997

Molecular cloning of the porcine beta-1,2-N-acetylglucosaminyltransferase II gene and assignment to chromosome 1q23-q27.

Glycosyltransferases play an important role in the synthesis of glycoproteins. Here we report the isolation of a brain cDNA coding for 89% of the porcine UDP-N-acetylglucosamine:alpha-6-D-mannoside-beta-1,2-N-acetylglucosaminy ltransferase II (EC 2.4.1.143) (GnTII). The cDNA was used for screening a genomic liver DNA library and isolation of a recombinant lambda FIX II phage containing the complete porcine GnTII gene and upstream and downstream sequences. The beta-1,2-N-acetylglucosaminyltransferase II gene harbours a single exon with an open reading frame of 1338 bp coding for a 446 amino acid protein with a calculated molecular mass of 51.1 kDa. The promoter of the GnTII gene is lacking a TATA-box and shows variable transcription start sites. In the 3'-untranslated region a polymorphic polyadenosine stretch was detected. The porcine GnTII gene contains four polyadenylation sites. PCR analysis of a porcine-rodent hybrid cell panel revealed the chromosomal location of the GnTII gene on SSC 1q23-q27. The mapping data of the cell panel were confirmed by fluorescence in situ hybridization (FISH) on metaphase chromosomes.

Animals↗