Abstract
Species: Mouse Locus name: Natriuretic peptide receptor 2 Locus symbol: Npr2 Map position: Chromosome (Chr) 4: D4Mit4-9.57 plus or minus 3.03-Npr2, Xpa-1.06 plus or minus 1.06-Baat-5.32 plus or minus 2.31-D4Mit44 Method of mapping: The Jackson Laboratory (Jackson BSS) interspecific backcross: (C57BL6/JEi x SPRET/Ei) F sub(1) x SPRET/Ei, N = 94. Data base deposit information: MGD-JNUM-36805 Allele detection: The location of mouse Npr2 was determined by analysis of DNA samples from 94 backcross progeny. Genomic DNA was digested with PvuII, electrophoresed in a 1% agarose gel, transferred to Gene Screen plus membrane (Du Pont), and probed with a super(32)P-dCTP random primer-labeled cDNA under stringent conditions: a band of 10 kb was specific to C57BL6/JEi; this band was chosen as the diagnostic band for allele typing panel. Bands of 7.7 kb, 4.4 kb, and 2.2 kb were common to both parental strains. Discussion: The mammalian family of natriuretic peptides comprises at least three peptides: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). These peptides function in mutual antagonism to the hypertensive renin-angiotensin-II-aldosterone system and promote low blood pressure. These hormone act via interaction with specific receptors. Three receptors have been characterized and cloned. Two of these receptors, NPRA and NPRB, are members of the receptor guanylyl cyclase family. In human, NPR1, NPR2, and NPR3 have been shown to map to Chromosomes (Chrs) 1, 9, and 5 respectively. In mouse, the Npr1 locus has been reported to map to Chr 3, but the map positions of the Npr2 and Npr3 loci are not yet known. In this report we present data assigning the mouse Npr2 to Chr 4. The rodent Npr1, Npr2, and Npr3 genes are members of a gene family encoding homologous cell surface glycoproteins that share 33% identity in amino acids. Although one member of this gene family, Npr3, is identified by its extracytoplasmic region homology to NPR-A and NPRB, these receptors also contain regions of homology to two other families of proteins: the guanylyl cyclases and the protein kinases. These structures imply that at least three different protein motifs were assembled to form a protoNPR/guanylyl cyclase, then underwent duplication to form NPRA and NPRB genes. This particular rearrangement is very ancient, since this structure has also been observed in two membrane guanylyl cyclases from sea urchin.