CONDENSED MATTER: STRUCTURE, MECHANICAL AND THERMAL PROPERTIES |
|
|
|
|
E224G Regulation of the PIP$_{2}$-Induced Gating Kinetics of Kir2.1 Channels |
Shu-Xi Ren1, Jun-Wei Li1, Su-Hua Zhang1, D. E. Logothetis2, Hai-Long An1**, Yong Zhan1** |
1Key Laboratory of Molecular Biophysics of Hebei Province, Institute of Biophysics, School of Sciences, Hebei University of Technology, Tianjin 300401 2Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Virginia, USA
|
|
Cite this article: |
Shu-Xi Ren, Jun-Wei Li, Su-Hua Zhang et al 2017 Chin. Phys. Lett. 34 016102 |
|
|
Abstract As a member of the inwardly rectifying K$^{+}$ channel (Kir) family, Kir2.1 allows K$^{+}$ to influx the cell more easily than to efflux, a biophysical phenomenon named inward rectification. The function of Kir2.1 is to set the resting membrane potential and modulate membrane excitability. It has been reported that residue E224 plays a key role in regulating inward rectification. The mutant Kir2.1 (E224G) displays weaker inward rectification than the WT channel. Gating of Kir2.1 depends on the membrane lipid, PIP$_{2}$, such that the channel gates are closed in the absence of PIP$_{2}$. Here we perform electrophysiological and computational approaches, and demonstrate that E224 also plays an important role in the PIP$_{2}$-dependent activation of Kir2.1 in addition to its influence on inward rectification. The E224G mutant takes 4.5 times longer to be activated by PIP$_{2}$. To probe the mechanism by which E224G slows the channel opening kinetics, we perform targeted molecular dynamics simulations and find that the mutant weakens the interactions between CD-loop and C-linker (H221-R189) and the adjacent G-loops (R312-E303) which are thought to stabilize the open state of the channel in our previous work. These data provide new insights into the regulation of Kir2.1 channel activity and suggest that a common mechanism may be involved in the distinct biophysical processes, such as inward rectification and PIP$_{2}$-induced gating.
|
|
Received: 05 August 2016
Published: 29 December 2016
|
|
PACS: |
61.80.Lj
|
(Atom and molecule irradiation effects)
|
|
87.16.dp
|
(Transport, including channels, pores, and lateral diffusion)
|
|
87.16.Vy
|
(Ion channels)
|
|
|
Fund: Supported by the National Natural Science Foundation for Distinguished Young Scholars of Hebei Province under Grant Nos C2015202340 and C2013202244, the Foundation for Outstanding Talents of Hebei Province under Grant No C201400305, the National Natural Science Foundation of China under Grant Nos 11247010, 11175055, 11475053, 11347017, 31400711 and 11647121, the NIH R01 under Grant No HL059949-18, the Foundation for the Science and Technology Program of Higher Education Institutions of Hebei Province under Grant No QN2016113, and the Scientific Innovation Fund for Excellent Young Scientists of Hebei University of Technology under Grant No 2015010. |
|
|
[1] | Hibino H, Inanobe A, Furutani K, Murakami S, Findlay I and Kurachi Y 2010 Physiol. Rev. 90 291 | [2] | Kubo Y, Baldwin T J, Jan Y N and Jan L Y 1993 Nature 362 127 | [3] | Doupnik C A, Davidson N and Lester H A 1995 Curr. Opin. Neurobiol. 5 268 | [4] | So I, Ashmole I, Davies N W, Sutcliffe M J and Stanfield P R 2001 J. Physiol. 531 37 | [5] | Guo D, Ramu Y, Klem A M and Lu Z 2003 J. Gen. Physiol. 121 261 | [6] | Lee S J, Wang S, Borschel W, Heyman S, Gyore J and Nichols C G 2013 Nat. Commun. 4 2786 | [7] | Caballero R, Dolz-Gaiton P, Gomez R, Amoros I, Barana A, Gonzalez De La Fuente M, Osuna L, Duarte J, Lopez-Izquierdo A, Moraleda I, Galvez E, Sanchez-Chapula J A, Tamargo J and Delpon E 2010 Proc. Natl. Acad. Sci. USA 107 15631 | [8] | Chang H K and Shieh R C 2013 Biochim. Biophys. Acta 1828 765 | [9] | Matsuda H, Saigusa A and Irisawa H 1987 Nature 325 156 | [10] | Lu Z and Mackinnon R 1994 Nature 371 243 | [11] | Fakler B, Brandle U, Bond C, Glowatzki E, Konig C, Adelman J P, Zenner H P and Ruppersberg J P 1994 FEBS Lett. 356 199 | [12] | Ficker E, Taglialatela M, Wible B A, Henley C M and Brown A M 1994 Science 266 1068 | [13] | Lopatin A N, Makhina E N and Nichols C G 1994 Nature 372 366 | [14] | Fakler B, Brandle U, Glowatzki E, Weidemann S, Zenner H P and Ruppersberg J P 1995 Cell 80 149 | [15] | Guo D and Lu Z 2003 J. Gen. Physiol. 122 485 | [16] | Thompson G A, Leyland M L, Ashmole I, Sutcliffe M J and Stanfield P R 2000 J. Physiol. 526 231 | [17] | Fujiwara Y and Kubo Y 2002 J. Gen. Physiol. 120 677 | [18] | Stanfield P R, Davies N W, Shelton P A, Sutcliffe M J, Khan I A, Brammar W J and Conley E C 1994 J. Physiol. 478 1 | [19] | Liu T A, Chang H K and Shieh R C 2012 J. Gen. Physiol. 139 245 | [20] | Xie L H, John S A, Ribalet B and Weiss J N 2004 J. Physiol. 561 159 | [21] | Huang C W and Kuo C C 2014 Pflügers Arch. 466 275 | [22] | Huang C L, Feng S and Hilgemann D W 1998 Nature 391 803 | [23] | Xiao J, Zhen X G and Yang J 2003 Nat. Neurosci. 6 811 | [24] | Kobrinsky E, Mirshahi T, Zhang H, Jin T and Logothetis D E 2000 Nat. Cell Biol. 2 507 | [25] | D'avanzo N, Lee S J, Cheng W W and Nichols C G 2013 J. Biol. Chem. 288 16726 | [26] | Taglialatela M, Ficker E, Wible B A and Brown A M 1995 EMBO J. 14 5532 | [27] | Yang J, Jan Y N and Jan L Y 1995 Neuron 14 1047 | [28] | Kubo Y and Murata Y 2001 J. Physiol. 531 645 | [29] | Zhang H, He C, Yan X, Mirshahi T and Logothetis D E 1999 Nat. Cell Biol. 1 183 | [30] | Soom M, Schonherr R, Kubo Y, Kirsch C, Klinger R and Heinemann S H 2001 FEBS Lett. 490 49 | [31] | Lopes C M, Zhang H, Rohacs T, Jin T, Yang J and Logothetis D E 2002 Neuron 34 933 | [32] | Li J, Lu S, Liu Y, Pang C, Chen Y, Zhang S, Yu H, Long M, Zhang H, Logothetis D E, Zhan Y and An H 2015 Sci. Rep. 5 11289 | [33] | Murata Y, Iwasaki H, Sasaki M, Inaba K and Okamura Y 2005 Nature 435 1239 | [34] | Murata Y and Okamura Y 2007 J. Physiol. 583 875 | [35] | Okamura Y, Murata Y and Iwasaki H 2009 J. Physiol. 587 513 | [36] | Kohout S C, Bell S C, Liu L, Xu Q, Minor D L, Jr. and Isacoff E Y 2010 Nat. Chem. Biol. 6 369 | [37] | Rodriguez-Menchaca A A, Adney S K, Tang Q Y, Meng X Y, Rosenhouse-Dantsker A, Cui M and Logothetis D E 2012 Proc. Natl. Acad. Sci. USA 109 E2399 | [38] | An H L, Lu S Q, Li J W, Meng X Y, Zhan Y, Cui M, Long M, Zhang H L and Logothetis D E 2012 J. Biol. Chem. 287 42278 | [39] | Sakata S, Hossain M I and Okamura Y 2011 J. Physiol. 589 2687 | [40] | Hansen S B, Tao X and Mackinnon R 2011 Nature 477 495 |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|