Leukemia inhibitory factor regulates trafficking of T-type Ca2+ channels

作者：Dey Deblina; Shepherd Andrew; Pachuau Judith; Martin Caraballo Miguel^*

来源：American Journal of Physiology - Cell Physiology, 2011, 300(3): C576-C587.

DOI：10.1152/ajpcell.00115.2010

• cytokine
• expression
• signaling

Dey D, Shepherd A, Pachuau J, Martin-Caraballo M. Leukemia inhibitory factor regulates trafficking of T-type Ca2+ channels. Am J Physiol Cell Physiol 300: C576-C587, 2011. First published December 22, 2010; doi:10.1152/ajpcell.00115.2010.-Neuropoietic cytokines such as ciliary neurotrophic factor (CNTF) and leukemia inhibitory factor (LIF) stimulate the functional expression of T-type Ca2+ channels in developing sensory neurons. However, the molecular and cellular mechanisms involved in the cytokine-evoked membrane expression of T-type Ca2+ channels are not fully understood. In this study we investigated the role of LIF in promoting the trafficking of T-type Ca2+ channels in a heterologous expression system. Our results demonstrate that transfection of HEK-293 cells with the rat green fluorescent protein (GFP)-tagged T-type Ca2+ channel (alpha 1)-Hsubunit resulted in the generation of transient Ca2+ currents. Overnight treatment of alpha(1H)-GFP-transfected cells with LIF caused a significant increase in the functional expression of T-type Ca2+ channels as indicated by changes in current density. LIF also evoked a significant increase in membrane fluorescence compared with untreated cells. Disruption of the Golgi apparatus with brefeldin A inhibited the stimulatory effect of LIF, indicating that protein trafficking regulates the functional expression of T-type Ca2+ channels. Trafficking of (alpha 1H)-GFP was also disrupted by cotransfection of HEK-293 cells with the dominant-negative form of ADP-ribosylation factor (ARF)1 but not ARF6, suggesting that ARF1 regulates the LIF-evoked membrane trafficking of (alpha 1H)-GFP subunits. Trafficking of T-type Ca2+ channels required transient activation of the JAK and ERK signaling pathways since stimulation of HEK-293 cells with LIF evoked a considerable increase in the phosphorylation of the downstream JAK targets STAT3 and ERK. Pretreatment of HEK-293 cells with the JAK inhibitor P6 or the ERK inhibitor U0126 blocked ERK phosphorylation. Both P6 and U0126 also inhibited the stimulatory effect of LIF on T-type Ca2+ channel expression. These findings demonstrate that cytokines like LIF promote the trafficking of T-type Ca2+ channels.

• 出版日期2011-3