کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4570687 | 1332064 | 2008 | 12 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Functional Interaction of the SNARE Protein NtSyp121 in Ca2+ Channel Gating, Ca2+ Transients and ABA Signalling of Stomatal Guard Cells Functional Interaction of the SNARE Protein NtSyp121 in Ca2+ Channel Gating, Ca2+ Transients and ABA Signalling of Stomatal Guard Cells](/preview/png/4570687.png)
ABSTRACTThere is now growing evidence that membrane vesicle trafficking proteins, especially of the superfamily of SNAREs, are critical for cellular signalling in plants. Work from this laboratory first demonstrated that a soluble, inhibitory (dominant-negative) fragment of the SNARE NtSyp121 blocked K+ and Cl– channel responses to the stress-related hormone abscisic acid (ABA), but left open a question about functional impacts on signal intermediates, especially on Ca2+-mediated signalling events. Here, we report one mode of action for the SNARE mediated directly through alterations in Ca2+ channel gating and its consequent effects on cytosolic-free [Ca2+] ([Ca2+]i) elevation. We find that expressing the same inhibitory fragment of NtSyp121 blocks ABA-evoked stomatal closure, but only partially suppresses stomatal closure in the presence of the NO donor, SNAP, which promotes [Ca2+]i elevation independently of the plasma membrane Ca2+ channels. Consistent with these observations, Ca2+ channel gating at the plasma membrane is altered by the SNARE fragment in a manner effective in reducing the potential for triggering a rise in [Ca2+]iand we show directly that its expression in vivo leads to a pronounced suppression of evoked [Ca2+]i transients. These observations offer primary evidence for the functional coupling of the SNARE with Ca2+ channels at the plant cell plasma membrane and, because [Ca2+]i plays a key role in the control of K+ and Cl– channel currents in guard cells, they underscore an important mechanism for SNARE integration with ion channel regulation during stomatal closure.
Journal: - Volume 1, Issue 2, March 2008, Pages 347–358