Rat prostatic steroid binding protein: DNA sequence and transcript maps of the two C3 genes

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• The rat possesses two non-allelic genes, C3(1) and C3(2), encoding the C3 polypeptide of prostatic steroid binding protein.
• Understanding the differential roles and regulation of these genes is crucial for comprehending prostatic function.

Purpose of the Study:

• To clone and sequence the two rat C3 genes.
• To elucidate the functional and regulatory differences between C3(1) and C3(2).

Main Methods:

• Gene cloning and DNA sequencing.
• Transcript mapping to identify distinct C3 transcripts.
• Analysis of gene homology and regulatory elements.

Main Results:

• Only the C3(1) gene produces authentic C3 polypeptide.
• Both genes exhibit high DNA sequence homology but differ in transcriptional activity.
• Two distinct C3 transcripts with shared 3' termini and separate 5' termini were identified.
• An identical repetitive element upstream of both genes and testosterone-mediated coordinate regulation were observed.

Conclusions:

• Differential gene expression and regulation contribute to the production of specific C3 transcripts.
• The C3(1) gene is the primary source of functional C3 in the rat prostate.
• Testosterone plays a key role in the coordinate regulation of both C3 genes.