Fluctuations in intracellular Ca2+ concentration elicited by inositol 1,4,5-trisphosphate (IP3) and the pyridine nucleotides, cyclic adenosine diphosphate-ribose (cADPR) and nicotinic acid adenine dinucleotide phosphate (NAADP) controls a variety of cellular processes ranging from fertilization to cell death.
The precise mechanisms that coordinate these stimulus-specific Ca2+ signalling pathways however remain to be elucidated. Conversely, evidences have suggested that organellar selection by these multiple Ca2+ mobilizing messengers may play a significant role.
Most recently, we have proposed that NAADP mobilizes endolysosomal Ca2+ stores by activating the two-pore segment channels (TPCs), in a manner that may be amplified by Ca2+-induced Ca2+-release ( CICR) from the sarco/endoplasmic reticulum (SR/ER), while others suggest that NAADP directly activates RyRs.
My current research focus on understanding the precise mechanism by which cADPR and NAADP mediate Ca2+ signalling in pulmonary arterial smooth muscle cells and other related cell types.
Area of research interest includes:
Ross FA, Rafferty JN, Dallas ML, Ogunbayo O, Ikematsu N, McClafferty H, Tian L, Widmer H, Rowe IC, Wyatt CN, Shipston MJ, Peers C, Hardie DG, Evans AM. (2011). Selective expression in carotid body type 1 cells of a single splice variant of the large conductance calcium- and voltage-activated potassium channel confers regulation by AMP-activated protein kinase. J Biol Chem. Apr 8; 286 (14):11929-36.
Ogunbayo OA, Sorrentino V, Galione A, Zhu MX, Evans A. (2010). Cyclic ADP-Ribose Activates Ryanodine Receptors While NAADP Activates Two Pore Channels. J Biol Chem. Mar 18; 286 (11):9136-40.
Hawley SA, Ross FA, Chevtzoff C, Green KA, Evans A, Fogarty S, Towler MC, Brown LJ, Ogunbayo OA, Evans AM, Hardie DG. (2010). Use of Cells expressing gamma subunit variants to identify diverse mechanisms of AMPK activation. Cell Metab. 11 (6): 554-65.
Evans AM, Hardie DG, Peers C, Wyatt CN, Viollet B, Kumar P, Dallas ML, Ross F, Ikematsu N, Jordan HL, Barr BL, Rafferty JN, Ogunbayo O. (2009). Ion channel regulation by AMPK: the route of hypoxia-response coupling in the carotid body and pulmonary artery. Ann N Y Acad. Sci. 1177: 89- 100.
This article was published on Jul 14, 2011