High impact information on Tm7

• These morphological differences appear to be correlated with the binding of protein to F-actin, since nuclear gel preparations incubated in tropomyosin, which also binds to actin filaments, appear similar to those treated with S-1 [1].
• During metamorphosis the adult-type area gradually expanded from dorsal to ventral slides with an anteroposterior gradient with increase in adult-type (adult-type MHC and beta-TM-positive) muscle fibers [2].
• In the present study we describe a cDNA clone (XTMalpha7) encoding a skeletal muscle isoform of the gene that differs from the previously described skeletal TM transcript (XTMalpha2) by its 3'UTR sequence [3].
• The Xenopus laevis alpha-tropomyosin (TM) gene, like its vertebrates counterparts, encodes muscle and non-muscle isoforms through two promoters and alternatively spliced exons [3].
• A full-length cDNA clone was isolated from an adult heart cDNA library using a nm TM-encoding cDNA probe [4].

Biological context of Tm7

• Characterization of muscle and non muscle Xenopus laevis tropomyosin mRNAs transcribed from the same gene. Developmental and tissue-specific expression [5].
• The Xenopus laevis TM-4 gene encodes non-muscle and cardiac tropomyosin isoforms through alternative splicing [4].
• Characterization of a TM-4 type tropomyosin that is essential for myofibrillogenesis and contractile activity in embryonic hearts of the Mexican axolotl [6].
• Transfection of ATmC-3 DNA into mutant hearts increased tropomyosin levels and promoted myofibrillogenesis [6].
• Comparative analyses of the deduced amino acid sequence of this cDNA with Xenopus skeletal muscle alpha-tropomyosin sequences indicate that the axolotl heart cDNA has 93% and 96% homology in the regions of amino acids 39-80 (exon 2b) and 258-284 (exon 9a), respectively [7].

Anatomical context of Tm7

• This TM is very similar to the members of the non-muscle (nm) TM family that includes rat TM-4, human TM30pl and chicken cardiac fibroblast FT-C [4].
• These data, together with published observations, demonstrated that, in this amphibian, the cardiac muscle TM are synthesized from the TM alpha and TM-4 genes [4].
• A full-length cDNA clone coding for a 248-amino-acid tropomyosin (TM) was isolated from a Xenopus laevis (Xl) oocyte cDNA library [4].

Analytical, diagnostic and therapeutic context of Tm7

• Northern blot analysis, with specific probes against each cDNA, was used to study the expression of the X. laevis alpha tropomyosin gene during development and in specific tissues [5].
• Our laboratory uses an animal model that carries a cardiac lethal mutation (gene c), this mutation results in a greatly diminished level of tropomyosin protein in the ventricle [6].
• The cDNA for alpha-tropomyosin (TM) was cloned by the polymerase chain reaction (PCR) from a lambda gt11 library constructed with mRNA from juvenile axolotl heart tissues [7].

References