Examination of differential glycoprotein preferences of N-acetylglucosaminyltransferase-IV isozymes a and b.

ABSTRACT: The N-glycans attached to proteins contain various GlcNAc branches, the aberrant formation of which correlates with various diseases. N-Acetylglucosaminyltransferase-IVa (GnT-IVa or MGAT4A) and Gnt-IVb (or MGAT4B) are isoenzymes that catalyze the formation of the β1,4-GlcNAc branch in N-glycans. However, the functional differences between these isozymes remain unresolved. Here, using cellular and UDP-Glo enzyme assays, we discovered that GnT-IVa and GnT-IVb have distinct glycoprotein preferences both in cells and in vitro. Notably, we show that GnT-IVb acted efficiently on glycoproteins bearing an N-glycan premodified by GnT-IV. To further understand the mechanism of this reaction, we focused on the noncatalytic C-terminal lectin domain, which selectively recognizes the product glycans. Re

SUBMITTER: Osada N 

PROVIDER: S-EPMC9478453 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature