期刊
BIOPHYSICAL JOURNAL
卷 110, 期 12, 页码 2759-2768出版社
CELL PRESS
DOI: 10.1016/j.bpj.2016.05.017
关键词
-
类别
资金
- National Institutes of Health [NIGMS-032842]
- National Institutes of Health Institutional Development Award (IDeA) [8P20GM103447]
- Children's Discovery Institute, National Science Foundation [CMMI-1265447]
- Directorate For Engineering
- Div Of Civil, Mechanical, & Manufact Inn [1265447] Funding Source: National Science Foundation
Motile cilia and flagella are whiplike cellular organelles that bend actively to propel cells or move fluid in passages such as airways, brain ventricles, and the oviduct. Efficient motile function of cilia and flagella depends on coordinated interactions between active forces from an array of motor proteins and passive mechanical resistance from the complex cytoskeletal structure (the axoneme). However, details of this coordination, including axonemal mechanics, remain unclear. We investigated two major mechanical parameters, flexural rigidity and interdoublet shear stiffness, of the flagellar axoneme in the unicellular alga Chlamydomonas reinhardtii. Combining experiment, theory, and finite element models, we demonstrate that the apparent flexural rigidity of the axoneme depends on both the intrinsic flexural rigidity (EI) and the elastic resistance to interdoublet sliding (shear stiffness, k(s)). We estimated the average intrinsic flexural rigidity and interdoublet shear stiffness of wild-type Chlamydomonas flagella in vivo, rendered immotile by vanadate, to be EI = 840 +/- 280pN.mu m(2) and k(s) = 79.6 +/- 10.5 pN/rad, respectively. The corresponding values for the pf3; cnk11-6 double mutant, which lacks the nexin-dynein regulatory complex (N-DRC), were EI = 1011 +/- 183 pN.mu m(2) and k(s) = 39.3 +/- 6.0 pN/rad under the same conditions. Finally, in the pf13A mutant, which lacks outer dynein arms and inner dynein arm c, the estimates were EI = 777 +/- 184 pN.mu m(2) and k(s) = 43.3 +/- 7.7 pN/rad. In the two mutant strains, the flexural rigidity is not significantly different from wild-type (p > 0.05), but the lack of N-DRC (in pf3; cnk11-6) or dynein arms (in pf13A) significantly reduces interdoublet shear stiffness. These differences may represent the contributions of the N-DRCs (similar to 40 pN/rad) and residual dynein interactions (similar to 35 pN/rad) to interdoublet sliding resistance in these immobilized Chlamydomonas flagella.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据