通过核磁共振光谱和分子建模对非肌肉肌球蛋白轻链激酶(nmMLCK)同工型进行结构-功能分析:MYLK变体的影响
Structure-Function Analysis of the Non-Muscle Myosin Light Chain Kinase (nmMLCK) Isoform by NMR Spectroscopy and Molecular Modeling: Influence of MYLK Variants.
作者信息
Shen Kui, Ramirez Benjamin, Mapes Brandon, Shen Grace R, Gokhale Vijay, Brown Mary E, Santarsiero Bernard, Ishii Yoshitaka, Dudek Steven M, Wang Ting, Garcia Joe G N
机构信息
Institute for Personalized Respiratory Medicine, Section of Pulmonary, Critical Care, Sleep, and Allergy, University of Illinois at Chicago, Chicago, Illinois, United States of America.
Center for Structural Biology, University of Illinois at Chicago, Chicago, Illinois, United States of America.
出版信息
PLoS One. 2015 Jun 25;10(6):e0130515. doi: 10.1371/journal.pone.0130515. eCollection 2015.
The MYLK gene encodes the multifunctional enzyme, myosin light chain kinase (MLCK), involved in isoform-specific non-muscle and smooth muscle contraction and regulation of vascular permeability during inflammation. Three MYLK SNPs (P21H, S147P, V261A) alter the N-terminal amino acid sequence of the non-muscle isoform of MLCK (nmMLCK) and are highly associated with susceptibility to acute lung injury (ALI) and asthma, especially in individuals of African descent. To understand the functional effects of SNP associations, we examined the N-terminal segments of nmMLCK by 1H-15N heteronuclear single quantum correlation (HSQC) spectroscopy, a 2-D NMR technique, and by in silico molecular modeling. Both NMR analysis and molecular modeling indicated SNP localization to loops that connect the immunoglobulin-like domains of nmMLCK, consistent with minimal structural changes evoked by these SNPs. Molecular modeling analysis identified protein-protein interaction motifs adversely affected by these MYLK SNPs including binding by the scaffold protein 14-3-3, results confirmed by immunoprecipitation and western blot studies. These structure-function studies suggest novel mechanisms for nmMLCK regulation, which may confirm MYLK as a candidate gene in inflammatory lung disease and advance knowledge of the genetic underpinning of lung-related health disparities.
MYLK基因编码多功能酶肌球蛋白轻链激酶(MLCK),该酶参与特定亚型的非肌肉和平滑肌收缩以及炎症期间血管通透性的调节。三个MYLK单核苷酸多态性(P21H、S147P、V261A)改变了MLCK非肌肉亚型(nmMLCK)的N端氨基酸序列,并且与急性肺损伤(ALI)和哮喘的易感性高度相关,尤其是在非洲裔个体中。为了了解单核苷酸多态性关联的功能影响,我们通过二维核磁共振技术1H-15N异核单量子相干(HSQC)光谱以及计算机模拟分子建模研究了nmMLCK的N端片段。核磁共振分析和分子建模均表明单核苷酸多态性定位于连接nmMLCK免疫球蛋白样结构域的环上,这与这些单核苷酸多态性引起的最小结构变化一致。分子建模分析确定了受这些MYLK单核苷酸多态性不利影响的蛋白质-蛋白质相互作用基序,包括支架蛋白14-3-3的结合,免疫沉淀和蛋白质印迹研究证实了这一结果。这些结构-功能研究揭示了nmMLCK调节的新机制,这可能证实MYLK是炎症性肺病的候选基因,并推进对肺部相关健康差异的遗传基础的认识。