In:
European Journal of Biochemistry, Wiley, Vol. 259, No. 1-2 ( 1999-01), p. 204-211
Abstract:
During the course of cloning and characterization of natriuretic peptide receptor‐A (NPR‐A) from the euryhaline fish eel, Anguilla japonica , we identified a splice variant with unique structural properties that affect ligand‐inducible intrinsic guanylate cyclase activity. The variant, generated from a splice between a cryptic donor site and the normal acceptor site, lacked nine amino acid residues (VFTKTGYYK) in the kinase‐like regulatory domain. This deletion of a very short segment resulted in the complete loss of the ligand inducibility of the cyclase activity. The nine‐amino acid segment may therefore be useful as a target for studies aimed at clarifying the mechanism of activation of the guanylate cyclase domain. Characterization of the normal form of eel NPR‐A also led to the following interesting findings. Although eel NPR‐A had a domain structure very similar to that of mammalian counterparts, it lacked the third cysteine residue in the extracellular domain which is conserved among mammalian NPR‐A molecules. The eel receptor bound both amidated and nonamidated eel atrial natriuretic peptide (eANP) with high affinity but, when assayed for ligand‐inducible cGMP generation, it responded efficiently only to physiological concentrations of the amidated ligand, suggesting that the biologically active form is the amidated eANP, and the nonamidated form acts as a partial antagonist; similarly, nonhomologous rat ligands behaved like antagonists toward the eel receptor in the concentration range 0.1–10 n m . The receptor message was found to be relatively abundant in the osmoregulatory organs such as the gill, kidney, intestine and urinary bladder.
Type of Medium:
Online Resource
ISSN:
0014-2956
,
1432-1033
DOI:
10.1046/j.1432-1327.1999.00023.x
Language:
English
Publisher:
Wiley
Publication Date:
1999
detail.hit.zdb_id:
1398347-7
detail.hit.zdb_id:
2172518-4
SSG:
12
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