|Title||Inositol 1,4,5-trisphosphate receptor 1, a widespread Ca2+ channel, is a novel substrate of polo-like kinase 1 in eggs.|
|Publication Type||Journal Article|
|Year of Publication||2008|
|Authors||Ito, J, Yoon, S-Y, Lee, B, Vanderheyden, V, Vermassen, E, Wojcikiewicz, R, Alfandari, D, De Smedt, H, Parys, JB, Fissore, RA|
|Date Published||2008 Aug 15|
To initiate embryo development, the sperm induces in the egg release of intracellular calcium ([Ca2+](i)). During oocyte maturation, the inositol 1,4,5-trisphosphate receptor (IP(3)R1), the channel implicated, undergoes modifications that enhance its function. We found that IP(3)R1 becomes phosphorylated during maturation at an MPM-2 epitope and that this persists until the fertilization-associated [Ca2+](i) responses cease. We also reported that maturation without ERK activity diminishes IP(3)R1 MPM-2 reactivity and [Ca2+](i) responses. Here, we show that IP(3)R1 is a novel target for Polo-like kinase1 (Plk1), a conserved M-phase kinase, which phosphorylates it at an MPM-2 epitope. Plk1 and IP(3)R1 interact in an M-phase preferential manner, and they exhibit close co-localization in the spindle/spindle poles area. This co-localization is reduced in the absence of ERK activity, as the ERK pathway regulates spindle organization and IP(3)R1 cortical re-distribution. We propose that IP(3)R1 phosphorylation by Plk1, and possibly by other M-phase kinases, underlies the delivery of spatially and temporally regulated [Ca2+](i) signals during meiosis/mitosis and cytokinesis.
|Alternate Journal||Dev. Biol.|