Qin Liying, Reger Albert S, Guo Elaine, Yang Matthew P, Zwart Peter, Casteel Darren E, Kim Choel
⊥Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
@Department of Medicine, University of California at San Diego, La Jolla, California 92093, United States.
Biochemistry. 2015 Jul 28;54(29):4419-22. doi: 10.1021/acs.biochem.5b00572. Epub 2015 Jul 15.
cGMP-dependent protein kinase (PKG) Iα is a central regulator of smooth muscle tone and vasorelaxation. The N-terminal leucine zipper (LZ) domain dimerizes and targets PKG Iα by interacting with G-kinase-anchoring proteins. The PKG Iα LZ contains C42 that is known to form a disulfide bond upon oxidation and to activate PKG Iα. To understand the molecular details of the PKG Iα LZ and C42-C42' disulfide bond, we determined crystal structures of the PKG Iα wild-type (WT) LZ and C42L LZ. Our data demonstrate that the C42-C42' disulfide bond dramatically stabilizes PKG Iα and that the C42L mutant mimics the oxidized WT LZ structurally.
环磷酸鸟苷依赖性蛋白激酶(PKG)Iα是平滑肌张力和血管舒张的核心调节因子。N端亮氨酸拉链(LZ)结构域通过与G激酶锚定蛋白相互作用形成二聚体并靶向PKG Iα。PKG Iα LZ包含C42,已知其在氧化时会形成二硫键并激活PKG Iα。为了解PKG Iα LZ和C42-C42'二硫键的分子细节,我们测定了PKG Iα野生型(WT)LZ和C42L LZ的晶体结构。我们的数据表明,C42-C42'二硫键极大地稳定了PKG Iα,并且C42L突变体在结构上模拟了氧化的WT LZ。