Core 2 GlcNAc transferase and kidney tubular cell-specific expression

Area of Science:

• Glycobiology
• Molecular Biology
• Genetics

Background:

• Glycan chain expression is tightly regulated in time and space.
• Core 2 beta-1,6-GlcNAc transferase plays a role in kidney glycolipid and glycoprotein synthesis.
• Polymorphic expression of kidney glycolipids in mice led to the identification of regulatory genes.

Purpose of the Study:

• To investigate the kidney tubular cell-specific regulation of core 2 beta-1,6-GlcNAc transferase.
• To identify the regulatory gene controlling the mRNA levels of this enzyme.
• To understand the evolutionary origin of the regulatory gene.

Main Methods:

• Genetic analysis to identify regulatory genes.
• Immunohistochemistry using anti-core 2-Le(x) monoclonal antibody.
• Western blotting to detect specific glycoproteins.
• In situ hybridization to confirm cell-specific mRNA expression.
• Phylogenetic analysis of gene sequences.

Main Results:

• The Gsl5 gene was identified as a regulator of kidney-specific core 2 beta-1,6-GlcNAc transferase mRNA.
• The enzyme utilizes specific glycolipids and glycoproteins with core 1 structures as substrates.
• Immunohistochemistry showed staining in proximal tubule cell vesicles.
• Western blotting detected a 500 kDa glycoprotein.
• In situ hybridization confirmed proximal tubular cell-specific regulation by Gsl5.
• Phylogenetic analysis suggests the Gsl5 gene emerged about one million years ago.

Conclusions:

• The Gsl5 gene controls the proximal tubular cell-specific expression of core 2 beta-1,6-GlcNAc transferase mRNA.
• This regulation impacts kidney glycolipid and glycoprotein synthesis.
• The functional Gsl5 gene likely arose during the subspeciation of Mus musculus.