Structural analysis of esp-1 gene (PRSS 21)

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• The esp-1 gene encodes a membrane-type serine protease originally identified in human eosinophils.
• It exhibits ubiquitous tissue expression, notably high in the testis, but is absent in kidney and muscle.
• While esp-1 is found in eosinophils, it is not detected in neutrophils, despite both cell types originating from myeloid progenitors.

Purpose of the Study:

• To clone and characterize the esp-1 gene's genomic structure and chromosomal location.
• To identify and analyze novel splicing variants of the esp-1 gene.
• To determine the transcription initiation site and identify regulatory elements within the esp-1 promoter region.

Main Methods:

• Genome cloning using a bacterial artificial chromosome (BAC) library.
• Exon-intron junction determination, radiation hybrid mapping, and fluorescence in situ hybridization (FISH).
• cDNA library screening, RNase protection assays, primer extension analysis, and dual-luciferase reporter assays.

Main Results:

• The esp-1 gene spans approximately 4.6 kb, comprising 6 exons and 5 introns.
• The gene was mapped to chromosome 16p13.3.
• A new splicing variant was identified, and the transcription initiation site was located at nucleotide position -106 (G).
• A GC-rich region (-106 to -189) with an AP-1/Sp-1 binding site was found to be essential for promoter activity in HeLa cells.

Conclusions:

• The genomic structure, localization, and a novel splicing variant of the esp-1 gene have been elucidated.
• Key regulatory elements, including the transcription start site and a critical promoter region, have been identified.
• This research provides a foundation for further investigation into the function and regulation of the esp-1 gene and its variants.