Molecular cloning of human gastrin precursor cDNA

Area of Science:

• Molecular Biology
• Genetics
• Gastroenterology

Background:

• Gastrin is a key hormone regulating gastric acid secretion.
• Understanding gastrin gene structure is crucial for studying gastrointestinal disorders.

Purpose of the Study:

• To clone and sequence the complementary DNA (cDNA) of human gastrin mRNA from the gastric antrum.
• To analyze the structure of the human gastrin precursor and compare it with its porcine counterpart.

Main Methods:

• Obtained a porcine gastrin precursor cDNA clone using a synthetic oligodeoxyribonucleotide probe.
• Utilized the porcine clone as a hybridization probe to isolate human gastrin precursor cDNA clones.
• Performed sequence analysis of the human gastrin cDNA, identifying 5' untranslated region, coding region, and 3' untranslated region.

Main Results:

• Successfully cloned human gastrin precursor cDNA from the gastric antrum.
• Sequence analysis revealed specific lengths for the 5' untranslated region (4 nucleotides), coding region (303 nucleotides), and 3' untranslated region (98 nucleotides).
• The deduced precursor molecule encodes for both big and small gastrin, flanked by basic amino acid pairs, and exhibits significant sequence homology with porcine gastrin, particularly in the active peptide region.

Conclusions:

• The study successfully elucidated the cDNA sequence of human gastrin precursor.
• High homology in the active peptide region between human and porcine gastrin suggests conserved biological function.
• This provides a foundation for further research into gastrin's role in gastric physiology and pathology.