The collapsin response mediator protein 1 (CRMP-1) and the promyelocytic leukemia zinc finger protein (PLZF) bind to UDP- N-acetylglucosamine 2-epimerase/ N-acetylmannosamine kinase (GNE), the key enzyme of sialic acid biosynthesis

Abstract

Sialic acids (Sia) are expressed as terminal sugars in many glycoconjugates. They are involved in a variety of cell–cell interactions and therefore play an important role during development and regeneration. UDP- N-acetylglucosamine 2-epimerase/ N-acetylmannosamine kinase (GNE) is the key enzyme in the de novo synthesis of Sia and it is a regulator of cell surface sialylation. Inactivation of GNE in mice results in early embryonic lethality. Mutations in the GNE gene are of clinical relevance in hereditary inclusion body myopathy, but these mutations do not necessarily decrease the enzymatic activity of GNE. In this study, we searched for novel function of the GNE protein beside its enzymatic function in the Sia biosynthesis. We here report the identification of novel GNE-interacting proteins. Using a human prey matrix we identified four proteins interacting with GNE in a yeast two-hybrid assay. For two of them, the collapsin response mediator protein 1 and the promyelocytic leukemia zinc finger protein, we could verify protein–protein interaction with GNE.