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A Krempler

Publications and source records attributed to A Krempler.

7 recordsLinked to original sources
PubMed2000

Molecular analysis and chromosomal assignment of the canine CALC-I/alpha-CGRP gene.

We have isolated a recombinant phage harboring the canine CALC-I/alpha-CGRP gene. The gene spans a region of approx. 5.3 kb and consists of six exons with sizes ranging from 95 bp (exon 2) and 494 bp (exon 4). By alternative splicing, two transcripts with ORFs of 390 and 384 nt are generated. These encode either the 32-amino acid-long hormone calcitonin (CALC) or the neurotransmitter calcitonin gene-related peptide (alpha-CGRP) with a length of 37 amino acids after proteolytic processing of precursor molecules. The canine calcitonin precursor consists of 130 amino acids with a molecular mass of 14.05 kDa and a statistical pI of 8.0, whereas the deduced alpha-CGRP precursor harbors 128 amino acids with a molecular mass of 13.87 kDa and a statistical pI of 8.6. Both polypeptides have a common N-terminal region of 76 amino acids that is encoded by exons 2 and 3 and separated by different eight (CALC) or six (alpha-CGRP) amino acid spacers from the biologically active polypeptide. The CALC-I/alpha-CGRP gene is a member of the calcitonin gene family and was assigned to chromosome CFA 16q25.1. A comparative analysis of different dog breeds revealed a breed-specific allelic d(CAGGAG)-hexanucleotide expansion in exon 3. This expansion results in an elongation of the common N-terminal region by two amino acids (glutamine-glutamic acid) and alters the molecular mass to 14.31 kDa (pI 7.9) and 14.13 kDa (pI 8.5) of the calcitonin and alpha-CGRP precursor, respectively.

Alternative Splicing↗
PubMed2000

Isolation and characterization of a new FHL1 variant (FHL1C) from porcine skeletal muscle.

Four and a half LIM domain protein 1 (FHL1) was initially described as an abundant skeletal muscle protein with four LIM domains and a GATA like zinc finger. FHL1 was shown to be expressed in skeletal muscle as well as in a variety of other tissues. Recently, alternatively spliced FHL1 mRNAs were identified coding for C-terminal truncated proteins. The tissue distribution of these variants is more restricted and their functional properties seem to be different. We have isolated and characterized a new variant of FHL1 from porcine skeletal muscle (FHL1C). FHL1C is characterized by a newly identified start codon resulting in a 16 amino acids longer N- terminal region. We have isolated and characterized the porcine FHL1C gene spanning approximately 14 kb and harboring six exons. Using primer extension analysis, the transcription start site of FHL1C was mapped, indicating that FHL1C is regulated by an alternative promoter. The tissue distribution of FHL1C expression was studied by RT-PCR. The porcine FHL1C gene was assigned to the distal part of the long arm of the X chromosome by fluorescence in situ hybridization and screening of a somatic porcine/rodent cell hybrid panel.

Alternative Splicing↗
PubMed1999

Zinc finger proteins: watchdogs in muscle development.

The specificity of highly differentiated tissues is largely achieved through the action of cell- and stage-restricted transcription factors. The basic events in skeletal muscle development are triggered by a unique family of myogenic basic helix-loop-helix proteins - MyoD, Myf-5, myogenin and MRF-4. Binding sites for these factors are found in the promoter regions of many genes whose expression is restricted to muscle cells, but the tight regulation of gene expression is dependent on the interaction of different factors. In this respect zinc finger proteins seem to play an important role, not only in the establishment of muscle cells but also in the maintenance of muscle function. This review discusses several zinc finger proteins that have been characterized as regulators of muscle development and muscle-specific gene expression.

Animals↗
PubMed1996

[Structure and expression of the porcine skeletal muscle ryanodine receptor gene].

The ryanodine receptors (RYR) are a family of intracellular Ca2+ release channels that were first identified in the terminal cistenae of the sarcoplasmic reticulum of the skeletal and cardiac muscle. Mutations within the skeletal muscle isoform were shown to cause malignant hyperthermia in swine and man. We have analysed the genomic structure of the porcine skeletal muscle ryanodine receptor and its expression using chimeric reporter gene constructs consisting of the RYR1 gene promoter and the chloramphenicol acetyltransferase gene after transfection in muscle and non-muscle cells.

Animals↗
PubMed1996

[Muscle specific gene expression during embryonal development].

The myogenic bHLH-proteins play a crucial role in the determination and tissue specific gene expression in skeletal muscle. Being able to regulate themselves and the other members of their family they establish the myogenic lineage in the precursor cells of the skeletal muscle. The precise mechanisms that lead to the manifestation of myogenic cells in vivo are still unknown, but much has been learned from the behaviour of established cell lines and targeted mutations in the myogenic regulatory factors (MRFs). This review will focus on the results of these experiments and outline the major regulatory pathways which lead to the formation of skeletal muscle cells.

Animals↗