Gene structural analysis and expression of human renal dipeptidase

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• Human renal dipeptidase (HRD) is an enzyme found in the kidneys.
• Understanding the genetic structure of HRD is crucial for its study.

Purpose of the Study:

• To isolate and characterize the human renal dipeptidase gene and its complementary DNA (cDNA).
• To investigate the structure, expression, and functional properties of human renal dipeptidase.

Main Methods:

• Isolation of human renal dipeptidase cDNA and genomic DNA from respective libraries.
• Gene sequencing to determine the structure (exons, introns) and amino acid sequence.
• Transfection of L929 cells to produce recombinant HRD.
• Northern blotting hybridization to analyze mRNA expression patterns.

Main Results:

• The human renal dipeptidase gene spans approximately 6 kb, comprising ten exons and nine introns.
• Both exons and cDNA encode a 411-amino acid precursor protein, including a signal sequence and a phosphatidylinositol glycan anchor sequence.
• Differences in cDNA compared to previous reports were identified as potential cloning artifacts, not allelic variants.
• Recombinant HRD produced in transfected cells demonstrated characteristics identical to native renal dipeptidase.
• Northern blotting confirmed that renal dipeptidase mRNA is exclusively transcribed in the kidney.

Conclusions:

• The study successfully isolated and characterized the human renal dipeptidase gene and cDNA.
• The findings provide insights into the genetic basis and tissue-specific expression of human renal dipeptidase.
• Recombinant HRD serves as a reliable model for studying the enzyme's function and properties.