We have isolated and sequenced a full-length cDNA clone of rat cardiac troponin I (TnI). The amino acid sequence of rat cardiac TnI is highly similar to that of other mammalian species in the portion of the molecule (residues 33-210) that is also homologous to skeletal muscle TnI isoforms. In contrast, a lower degree of similarity is present in the cardiac TnI-specific amino terminal extension (residues 1-32). This region contains a conserved serine residue that has been shown to be selectively phosphorylated by cAMP-dependent protein kinase. Cardiac TnI mRNA is weakly expressed in the 18-day fetal heart and accumulates in neonatal and postnatal stages. No difference can be demonstrated between TnI mRNAs present in fetal and postnatal heart by RNAase protection assays. The fetal and neonatal, but not the adult heart, contain significant amounts of slow skeletal TnI transcripts, detected by oligonucleotide probes specific for the 5'- and 3'-untranslated regions of slow skeletal TnI mRNA. In situ hybridization studies show that cardiac and slow skeletal TnI mRNAs are coexpressed in the rat heart from embryonic day 11 throughout fetal and perinatal stages. Changes in troponin isoform expression during development may be responsible for the difference in calcium sensitivity and in the response to beta-adrenergic stimulation between fetal and adult heart.

Developmental expression of rat cardiac troponin I mRNA.

AUSONI, SIMONETTA;GORZA, LUISA;SCHIAFFINO, STEFANO
1991

Abstract

We have isolated and sequenced a full-length cDNA clone of rat cardiac troponin I (TnI). The amino acid sequence of rat cardiac TnI is highly similar to that of other mammalian species in the portion of the molecule (residues 33-210) that is also homologous to skeletal muscle TnI isoforms. In contrast, a lower degree of similarity is present in the cardiac TnI-specific amino terminal extension (residues 1-32). This region contains a conserved serine residue that has been shown to be selectively phosphorylated by cAMP-dependent protein kinase. Cardiac TnI mRNA is weakly expressed in the 18-day fetal heart and accumulates in neonatal and postnatal stages. No difference can be demonstrated between TnI mRNAs present in fetal and postnatal heart by RNAase protection assays. The fetal and neonatal, but not the adult heart, contain significant amounts of slow skeletal TnI transcripts, detected by oligonucleotide probes specific for the 5'- and 3'-untranslated regions of slow skeletal TnI mRNA. In situ hybridization studies show that cardiac and slow skeletal TnI mRNAs are coexpressed in the rat heart from embryonic day 11 throughout fetal and perinatal stages. Changes in troponin isoform expression during development may be responsible for the difference in calcium sensitivity and in the response to beta-adrenergic stimulation between fetal and adult heart.
1991
File in questo prodotto:
File Dimensione Formato  
Ausoni et al. Development .pdf

accesso aperto

Tipologia: Published (publisher's version)
Licenza: Accesso gratuito
Dimensione 4.79 MB
Formato Adobe PDF
4.79 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11577/124857
Citazioni
  • ???jsp.display-item.citation.pmc??? 7
  • Scopus 67
  • ???jsp.display-item.citation.isi??? 69
  • OpenAlex ND
social impact