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M W Berchtold

Publications and source records attributed to M W Berchtold.

At least 19 recordsLinked to original sources
PubMed1992

The genes for the highly homologous Ca(2+)-binding proteins oncomodulin and parvalbumin are not linked in the human genome.

The chromosomal loci of the human parvalbumin and oncomodulin single-copy genes that encode structurally and evolutionarily closely related Ca(2+)-binding proteins were determined by somatic cell hybrid analysis. Southern blot analysis of genomic DNA from 25 human-hamster somatic cell hybrids showed that the human gene for oncomodulin resides on chromosome 7. Analysis of human-mouse hybrids selectively retaining human chromosome 7 or a portion of it allowed specific assignment of the gene locus to the p11-p13 region of chromosome 7 known to be mutated or deleted in patients with the Greig cephalopolysyndactyly syndrome. By gene dosage analysis on Southern blots, we showed that the gene for human parvalbumin maps distally to the cat eye syndrome marker D22S9 on chromosome 22q. Using somatic cell hybrids containing parts of human chromosome 22, the parvalbumin gene was sublocalized to the region 22q12-q13.1. This region contains a linkage group that maps to mouse chromosome 15, region E, and includes the SIS, ARSA, and DIA 1 genes. Our findings are consistent with the recent localization of the mouse parvalbumin gene to this region by two independent methods (C. H. Zühlke et al., 1989, Genet. Res. 54:37-43; S. Adolph et al., 1989, Cytogenet. Cell Genet. 52:177-179).

Animals↗
PubMed1992

[Signal transduction in normal and neoplastic cells].

This review describes molecular mechanisms involved in intracellular signal transmission. Special focus is given on calcium and calcium binding proteins as signaling intermediates. These strictly controlled biochemical reactions prevent uncoordinated proliferation which may lead to tumor development. Generally, signal transduction pathways are very similar among higher eukaryotes. Mutations in genes responsible for signal transmission and growth control (protooncogenes and tumor suppressor genes) are often found in tumors or cancer cell lines.

Animals↗
PubMed1991

Isolation and analysis of a human cDNA highly homologous to the yeast gene encoding L17A ribosomal protein.

A cDNA from human brain poly(A)+RNA with significant similarity to the gene encoding yeast L17A large subunit ribosomal (r) protein (L17A) was isolated using the polymerase chain reaction. The deduced amino acid (aa) sequence of 140 aa (calculated pI of 10.79) exhibits a 78% similarity to that of the yeast L17A r protein (88% when conservative aa replacements are considered as well). This indicates that L17A is one of the best conserved r-proteins and therefore may play a critical role in ribosome function. In contrast to its eubacterial and chloroplast counterparts, human L17A contains an N-terminal extension of 19 aa which may be involved in nuclear targeting of the r-protein. Approximately five to seven genes in mammalian genomes give strong hybridization signals when probed with the human L17A homologue cDNA. Whereas the L17A homologue was found to be expressed at similar levels in several human tissues as a transcript of 600 nucleotides, a several-fold higher transcript level was detected in the rapidly growing neuroblastoma cell line, SK-N-BE.

Amino Acid Sequence↗
PubMed1989

Parvalbumin genes from human and rat are identical in intron/exon organization and contain highly homologous regulatory elements and coding sequences.

The structural organization of the chromosomal gene for human parvalbumin was determined mostly by sequencing exons and intron exon junctions of a 7500 base-pair (bp) long genomic clone derived from a chromosome 22-specific gene library. Four exons coding for 100 from a total of 109 amino acids were detected in this clone and 472 bp of the 5'-flanking region were sequenced. The region corresponding to the C-terminal amino acids 101 to 109 of human parvalbumin was determined by sequencing a cDNA fragment derived from human brain mRNA after amplification by the polymerase chain reaction. The first intron is placed 7 bp upstream from the ATG translation start signal, whereas all other splice sites divide putative Ca2+-binding domains. All intron positions coincide exactly with those reported for the rat parvalbumin gene. The 5' mRNA leader sequence has a similarity of 57%, the coding region of 91% and the 3' non-coding region of 83% to the corresponding rat sequences. Only nine conservative amino acid replacements were observed between human and rat parvalbumins. The predicted secondary structures for human, rat, mouse and rabbit parvalbumins are very similar, indicating a strong structural relationship among mammalian parvalbumins. Several elements with potential transcription regulatory activities were found in the region immediately 5' to the transcription start site including a TATA box (TATATA) and a CAAT box (CCAAAAT). Several regions in the putative promoter are strongly conserved between the human and rat parvalbumin genes. One of these with a length of 32 bp is identical with the rat counterpart and has a high degree of homology to a promoter region in the myosin light chain 3F gene, which is expressed in fast contracting/relaxing muscle fibers (anaerobic/type IIb), the cell type that also exhibits highest levels of parvalbumin expression. The human parvalbumin mRNA contains the putative polyadenylation signal AATAAA 13 nucleotides upstream from the polyadenylation site. A 700-nucleotide long parvalbumin mRNA is synthesized at low levels in the human cerebellum as well as in the neuroblastoma cell line SK-N-BE.

Amino Acid Sequence↗
PubMed1989

A chemically transformed rat fibroblast cell line expresses high levels of oncomodulin.

Chemically (by N-methyl-N'-nitro-N-nitrosoguanidine) treated rat fibroblasts (T14c) exhibited growth characteristics and a morphology typical for transformed cells and markedly different from untreated, parental cells. In contrast to untransformed cells, T14c fibroblasts produced significant levels of oncomodulin mRNA as analyzed on Northern blots even when compared to rat Morris hepatomas, the richest source of oncomodulin known so far. The levels of transcripts for both calmodulin and oncomodulin in T14c cells were higher in log phase growth as compared to confluent stages. The T14c model system may be useful in the elucidation of mechanisms involved in the regulation of oncomodulin synthesis.

Animals↗
PubMed1989

Isolation and analysis of a rat genomic clone containing a long terminal repeat with high similarity to the oncomodulin mRNA leader sequence.

The structure of a novel long terminal repeat (LTR) from an intracisternal A particle (IAP) DNA element in the rat (Sprague-Dawley) genome was determined. This LTR has a total length of 313 base pairs (bp). Several structural features typical for retroviral LTR promoters were identified, including a "CCAAT" box, a "TATA" box, a polyadenylation signal, and a polyadenylation site. The LTR is flanked by 3-bp inverted repeats, and it consists of the three typical LTR regions, U3, R, and U5. U3 contains 213 bp, R 46 bp, and U5 54 bp, which is within the usual size range of IAP LTRs. A sequence of 60 bp in the U3 region reveals considerable similarity to a murine IAP LTR U3 element, which is known to interact with nuclear proteins. A sequence of 69 bp in the U5 and R regions has 83 and 93% similarities to an endogenous retroviral LTR from Syrian hamster and to the cDNA leader sequence of (Buffalo) rat oncomodulin, respectively. Oncomodulin is an "EF-hand" Ca2+-binding protein and appears in many human and rodent tumors and in cells with tumor-like properties but not in normal tissues. We postulate that in the rat the tumor-specific expression of oncomodulin is controlled by a retroviral LTR promoter.

Animals↗
PubMed1989

Localization of parvalbumin mRNA in rat brain by in situ hybridization histochemistry.

Parvalbumin mRNA was localized in rat brain by in situ hybridization using a 35S labelled rat parvalbumin cDNA and a synthetic oligodeoxyribonucleotide (corresponding to base sequences 140 to 183 of rat parvalbumin cDNA). Strongest hybridization signals were detected in the Purkinje cells of the cerebellum and in neurones of the reticular nucleus of the thalamus. Signal was also detected in the cerebral cortex, hippocampus, basal ganglia and brain stem in agreement with the distribution of parvalbumin immunoreactivity.

Animals↗
PubMed1989

Fine localization of genes on distal murine chromosome 15.

The following genes were localized by in situ hybridization on distal chromosome 15 of the mouse: thyroglobulin (Tgn) to 15D3/E, parvalbumin (Pva) to 15E, and the NADH-dependent cytosolic form of glycerol-3-phosphate dehydrogenase (Gdc-1) to 15F1-3. These genes belong to three different conserved chromosomal linkage groups on human chromosomes 8, 22, and 12, respectively.

Animals↗
PubMed1988

Opposite regulation of the mRNAs for parvalbumin and p19/6.8 in myotonic mouse muscle.

The gene mutation in the mouse, 'arrested development of righting response', adr, causes a defect of chloride conductance of the muscle fibre membrane leading to the symptoms of myotonia [Mehrke, G., Brinkmeier, H. and Jockusch, H. (1988) Muscle & Nerve 11, 440-446]. In fast muscle, the myotonic phenotype is accompanied by a drastic reduction of the Ca2+-binding protein, parvalbumin. Messenger RNA levels in organs of myotonic (ADR) mice were analysed. In fast muscles of the mutant, in-vitro-translatable parvalbumin mRNA was strongly reduced, whereas the mRNA for the slow-muscle-specific protein, p19/6.8, was increased. In contrast, the parvalbumin mRNA in the cerebellum was not affected by the adr mutation. A reduction of the two parvalbumin mRNA species (700 and 1100 nucleotides) in ADR fast muscle and unaltered parvalbumin mRNA levels in mutant cerebella were demonstrated by cDNA/mRNA hybridisation, using a rat parvalbumin cDNA as a probe. The mRNA level for another Ca2+-binding protein, calmodulin, was low in muscle and high in the central nervous system but was unaffected by the mutation. When adr/adr mice were fed a diet containing the membrane-stabilising drug, tocainide, the levels in muscle of the mRNAs for parvalbumin and p19/6.8 were partially normalised.

Animals↗
PubMed1988

Increased calmodulin synthesis in the pre-replicative phase of rat liver regeneration.

A cytosolic calmodulin wave has been described in the pre-replicative phase of rat liver regeneration. Here we demonstrate that this calmodulin increase is reduced by injection of cycloheximide (translation inhibitor) and actinomycin D (transcription inhibitor). In addition, we found that calmodulin mRNA levels are increased during the early pre-replicative period of liver regeneration, and this increase is affected by actinomycin D. Together, these results strongly indicate that the calmodulin wave observed in the pre-replicative phase of liver regeneration is due to de novo synthesis of this protein.

Animals↗
PubMed1987

Structural organization and chromosomal assignment of the parvalbumin gene.

The structure of the rat parvalbumin gene has been elucidated from analysis of six overlapping clones isolated from a rat lambda Charon 4A genomic library. Two of the clones were mapped in detail, and all exons were localized by Southern hybridization using fragments of a full-length parvalbumin cDNA (Epstein, P., Means, A. R., and Berchtold, M. W. (1986) J. Biol. Chem. 261, 5886-5891). The rat parvalbumin transcription unit is 15.5 kilobase pairs in length and contains four introns. The first intron divides the 5'-nontranslated region, whereas the other three interrupt coding DNA. All intron/extron boundaries were sequenced as was 377 base pairs immediately 5' from the putative transcription initiation site. The promoter region contains eukaryotic regulatory homologies to the "TATA" box at -24 and "CAAT" box at -47 and -156. In addition, two doublets consisting of 11-base pair direct repeats exist in the promoter region. Parvalbumin binds two Ca2+, whereas many other members of the same superfamily bind four. Comparison of the genes that encode these proteins provides a strong confirmation of the hypothesis that parvalbumin evolved from an ancestral gene specifying a four-domain Ca2+-binding protein. The rat parvalbumin gene was also utilized to assign its human counterpart to chromosome 22 from data obtained by hybridization to DNA from a somatic cell hybrid panel. It was also used to isolate a 7.5-kilobase pair EcoRI fragment from a human chromosome 22 DNA library.

Amino Acid Sequence↗
PubMed1987

Ca2+-binding parvalbumin in rat testis. Characterization, localization, and expression during development.

Parvalbumin, a Ca2+-binding protein, was isolated from rat testis. This is the first demonstration of the protein in endocrine glands. By using a rat parvalbumin cDNA probe, parvalbumin mRNA was demonstrated in the testis, indicating that the protein is synthesized in this tissue and that testis parvalbumin is a product of the same gene as the one encoding for muscle parvalbumin. Parvalbumin was localized by immunohistochemical methods in the Leydig cells and in the acrosome region of maturing spermatids (stages 1-15). The expression of parvalbumin during testis development was followed. High parvalbumin protein and mRNA levels were found at stages of highest Leydig cell activity, i.e. at late fetal stages until birth and again around postnatal day 50. This suggests that parvalbumin may be involved in the production of testosterone in Leydig cells, a process which is highly dependent on calcium.

Acrosome↗