Cloning and sequence analysis of cDNA encoding urotensin I precursor

Area of Science:

• Neuroendocrinology
• Molecular Biology
• Evolutionary Biology

Background:

• Urotensin I is a neuropeptide hormone originating from the caudal neurosecretory system in carp (Cyprinus carpio).
• Understanding the precursor structure is crucial for elucidating its synthesis and function.

Purpose of the Study:

• To determine the primary structure of the urotensin I precursor in carp.
• To investigate the evolutionary relationship between urotensin I and mammalian hormones.
• To identify the specific tissue expression of the mRNA encoding the urotensin I precursor.

Main Methods:

• Analysis of the nucleotide sequence of cloned complementary DNA (cDNA) to the encoding mRNA.
• RNA transfer blot analysis to detect mRNA presence in different carp tissues.

Main Results:

• The precursor consists of 145 amino acid residues.
• The urotensin I sequence (41 amino acids) is located at the carboxyl terminus, flanked by Lys-Arg and Gly-Lys.
• Sequence homology suggests an evolutionary relationship between carp urotensin I precursors and mammalian corticotropin-releasing factors.
• mRNA encoding the precursor is exclusively detected in the carp spinal cord.

Conclusions:

• The primary structure of the carp urotensin I precursor has been elucidated.
• Carp urotensin I and mammalian corticotropin-releasing factors share evolutionary origins.
• The expression of urotensin I precursor mRNA is localized to the spinal cord in carp.