Question

How does an inhibitor of n-acetylglucosamine phosphotransferase affect lysosomal protein sorting?

Answer 1

Answer;

Lysosomal proteins are secreted from the cell

Explanation;

• N-acetylglucosamine phosphotransferase is a golgi-localized enzyme that catalyzes the first step in the synthesis of the mannose 6-phosphate recognition marker on lysosomal acid hydrolases.
• The loss of function of this enzyme results in impaired lysosomal targeting of the acid hydrolases and decreased lysosomal degradation.
• Mannose 6-phosphate receptor sorts lysosomal hydrolases in trans Golgi Network; the first step is the recognition of lysosomal hydrolyses in the Golgi apparatus by  N-acetylglucosamine phosphotransferase.
• The enzyme has both the catalytic sites which binds both high mannose N-linked oligosaccharides and UDP-GlcNAc, and recognition site that binds to a signal patch present only on the surface of lysosomal hydrolases.