Exp Mol Med.  2015 Aug;47(8):e177. 10.1038/emm.2015.48.

N-acetyl-D-glucosamine kinase interacts with dynein light-chain roadblock type 1 at Golgi outposts in neuronal dendritic branch points

• Islam MA
• Sharif SR
• Lee H
• Seog DH
• Moon IS

• KMID: 2155431
• DOI: http://doi.org/10.1038/emm.2015.48

Abstract

N-acetylglucosamine kinase (GlcNAc kinase or NAGK) is a ubiquitously expressed enzyme in mammalian cells. Recent studies have shown that NAGK has an essential structural, non-enzymatic role in the upregulation of dendritogenesis. In this study, we conducted yeast two-hybrid screening to search for NAGK-binding proteins and found a specific interaction between NAGK and dynein light-chain roadblock type 1 (DYNLRB1). Immunocytochemistry (ICC) on hippocampal neurons using antibodies against NAGK and DYNLRB1 or dynein heavy chain showed some colocalization, which was increased by treating the live cells with a crosslinker. A proximity ligation assay (PLA) of NAGK-dynein followed by tubulin ICC showed the localization of PLA signals on microtubule fibers at dendritic branch points. NAGK-dynein PLA combined with Golgi ICC showed the colocalization of PLA signals with somal Golgi facing the apical dendrite and with Golgi outposts in dendritic branch points and distensions. NAGK-Golgi PLA followed by tubulin or DYNLRB1 ICC showed that PLA signals colocalize with DYNLRB1 at dendritic branch points and at somal Golgi, indicating a tripartite interaction between NAGK, dynein and Golgi. Finally, the ectopic introduction of a small peptide derived from the C-terminal amino acids 74-96 of DYNLRB1 resulted in the stunting of hippocampal neuron dendrites in culture. Our data indicate that the NAGK-dynein-Golgi tripartite interaction at dendritic branch points functions to regulate dendritic growth and/or branching.

MeSH Terms

Amino Acid Sequence
Animals
Cells, Cultured
Cytoplasmic Dyneins/chemistry/*metabolism
Dendrites/metabolism
Golgi Apparatus/metabolism
HEK293 Cells
Hippocampus
Humans
Molecular Sequence Data
Neurons/*metabolism
Phosphotransferases (Alcohol Group Acceptor)/*metabolism
Protein Interaction Maps
Rats, Sprague-Dawley
Tubulin
Cytoplasmic Dyneins
Phosphotransferases (Alcohol Group Acceptor)
Tubulin