Atrial cardiocytes contain granules typical of protein-secreting cells, and atrial extracts are known to contain a powerful natriuretic and diuretic activity and to possess smooth muscle relaxant activity. A variety of active atrial peptides have been isolated, including a family of related peptides showing natriuretic, diuretic and smooth muscle relaxant activities in rat and human atria; these peptides were named atrial natriuretic factor (ANF). Another unrelated peptide from pig atria, cardiodilatin, is thought to possess only smooth muscle relaxant activity. Its partial amino acid sequence shows no homology with ANF sequences. The sequence analysis of a large form (106 amino acids) of ANF and of ANF complementary DNA clones indicates that cardiodilatin and ANF peptides are synthesized from a common precursor. This precursor also contains a signal peptide sequence expected of a secretory protein. We now describe the complete structure and sequence of the human gene for this novel hormone precursor that we call pronatriodilatin.

SOURCE/DESCRIPTION pJAllO is a 1 Kb BamHI-XhoII human genomic fragment containing the first and second exons of the hPND gene (1). POLYMORPHISM XhoI detects two allelic fragments of 10 and 12 Kb. FREQUENCY Studied in 79 unrelated French Canadians. 10 Kb allele: 0.54 12 Kb allele: 0.46 NOT POLYMORPHIC FOR EcoRI, BamHI, XbaI, SacI and HindIII.CHROMOSOMAL LOCALISATION: hPND gene was mapped to the distal short arm of chromosome 1 by in situ hybridization and southern blot analysis of DNA from human-hamster somatic cell hybrids (2). MENDELIAN INHERITANCECo-dominant segregation observed in 9 families (43 individuals).

No abstract