Structure of rat atrial natriuretic factor precursor deduced from cDNA sequence

Area of Science:

• Cardiovascular Physiology
• Molecular Endocrinology

Background:

• The heart atrium produces peptides known as atrial natriuretic factors (ANFs).
• ANFs exhibit diuretic and smooth-muscle-relaxing properties, suggesting a role in fluid and vascular regulation.
• Multiple ANF peptides of varying sizes have been identified, hinting at a common precursor.

Purpose of the Study:

• To investigate the hypothesis that different ANF peptides originate from a single precursor.
• To clone and sequence the complementary DNA (cDNA) of the ANF precursor from rat atrial messenger RNA (mRNA).

Main Methods:

• Cloning of ANF precursor cDNAs using rat atrial mRNA.
• Determination of the nucleotide sequence of the cloned cDNAs.
• Deduction of the amino acid sequence of the ANF precursor.

Main Results:

• The ANF precursor was cloned and its nucleotide sequence determined.
• The deduced amino acid sequence comprises 152 residues.
• This precursor sequence encompasses the sequences of all previously reported ANF peptides.

Conclusions:

• The findings support the hypothesis that various ANF peptides are derived from a single precursor through proteolysis.
• The cloned precursor sequence provides a molecular basis for understanding ANF diversity and function.
• This research elucidates the molecular origins of ANF peptides involved in cardiovascular and fluid homeostasis.