Cooperative roles of glucose and asparagine-linked glycosylation in T-type calcium channel expression
- 328 Downloads
T-type calcium channels are key contributors to neuronal physiology where they shape electrical activity of nerve cells and contribute to the release of neurotransmitters. Enhanced T-type channel expression has been causally linked to a number of pathological conditions including peripheral painful diabetic neuropathy. Recently, it was demonstrated that asparagine-linked glycosylation not only plays an essential role in regulating cell surface expression of Cav3.2 channels, but may also support glucose-dependent potentiation of T-type currents. However, the underlying mechanisms by which N-glycosylation and glucose levels modulate the expression of T-type channels remain elusive. In the present study, we show that site-specific N-glycosylation of Cav3.2 is essential to stabilize expression of the channel at the plasma membrane. In contrast, elevated external glucose concentration appears to potentiate intracellular forward trafficking of the channel to the cell surface, resulting in an increased steady-state expression of the channel protein at the plasma membrane. Collectively, our study indicates that glucose and N-glycosylation act in concert to control the expression of Cav3.2 channels, and that alteration of these mechanisms may contribute to the altered expression of T-type channels in pathological conditions.
KeywordsCalcium channel T-type channel Cav3.2 Glucose N-glycosylation Trafficking
We are grateful to Drs. Michael E. Daily and Steven H. Green (University of Iowa) for providing the LcK-GFP construct.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
Work in the Weiss laboratory is supported by the Czech Science Foundation (grant 15-13556S), the Czech Ministry of Education Youth and Sports (grant 7AMB15FR015), and the Institute of Organic Chemistry and Biochemistry (IOCB). Y.R. and J.L. are supported by an IOCB postdoctoral fellowship.
- 9.García-Caballero A, Gadotti VM, Stemkowski P, Weiss N, Souza IA, Hodgkinson V, Bladen C, Chen L, Hamid J, Pizzoccaro A, Deage M, François A, Bourinet E, Zamponi GW (2014) The deubiquitinating enzyme USP5 modulates neuropathic and inflammatory pain by enhancing Cav3.2 channel activity. Neuron 83(5):1144–1158CrossRefPubMedGoogle Scholar
- 10.Jagodic MM, Pathirathna S, Joksovic PM, Lee W, Nelson MT, Naik AK, Su P, Jevtovic-Todorovic V, Todorovic SM (2008) Upregulation of the T-type calcium current in small rat sensory neurons after chronic constrictive injury of the sciatic nerve. J Neurophysiol 99(6):3151–3156CrossRefPubMedPubMedCentralGoogle Scholar
- 11.Jagodic MM, Pathirathna S, Nelson MT, Mancuso S, Joksovic PM, Rosenberg ER, Bayliss DA, Jevtovic-Todorovic V, Todorovic SM (2007) Cell-specific alterations of T-type calcium current in painful diabetic neuropathy enhance excitability of sensory neurons. J Neurosci 27(12):3305–3316CrossRefPubMedGoogle Scholar
- 16.Liu B, Spearman M, Doering J, Lattová E, Perreault H, Butler M (2014) The availability of glucose to CHO cells affects the intracellular lipid-linked oligosaccharide distribution, site occupancy and the N-glycosylation profile of a monoclonal antibody. J Biotechnol 170:17–27CrossRefPubMedGoogle Scholar
- 23.Orestes P, Osuru HP, McIntire WE, Jacus MO, Salajegheh R, Jagodic MM, Choe W, Lee J, Lee SS, Rose KE, Poiro N, Digruccio MR, Krishnan K, Covey DF, Lee JH, Barrett PQ, Jevtovic-Todorovic V, Todorovic SM (2013) Reversal of neuropathic pain in diabetes by targeting glycosylation of Ca (V)3.2 T-type calcium channels. Diabetes 62(11):3828–3838CrossRefPubMedPubMedCentralGoogle Scholar
- 27.Rzhepetskyy Y, Lazniewska J, Proft J, Campiglio M, Flucher BE, Weiss N (2016) A Cav3.2/Stac1 molecular complex controls T-type channel expression at the plasma membrane. Channels (Austin):1–9Google Scholar
- 28.Sano M, Korekane H, Ohtsubo K, Yamaguchi Y, Kato M, Shibukawa Y, Tajiri M, Adachi H, Wada Y, Asahi M, Taniguchi N (2012) N-glycans of SREC-I (scavenger receptor expressed by endothelial cells): essential role for ligand binding, trafficking and stability. Glycobiology 22(5):714–724CrossRefPubMedGoogle Scholar
- 32.Senatore A & Spafford JD (2015). Physiology and pathology of voltage-gated T-type calcium channels. In T-type Calcium Channels in Basic and Clinical Science pp. 3–17. Springer,Google Scholar
- 38.Weiss N, Hameed S, Fernández-Fernández JM, Fablet K, Karmazinova M, Poillot C, Proft J, Chen L, Bidaud I, Monteil A, Huc-Brandt S, Lacinova L, Lory P, Zamponi GW, De Waard M (2012) A Ca (v)3.2/syntaxin-1A signaling complex controls T-type channel activity and low-threshold exocytosis. J Biol Chem 287(4):2810–2818CrossRefPubMedGoogle Scholar