학술논문

Speed and Diffusion of Kinesin-2 Are Competing Limiting Factors in Flagellar Length-Control Model
Document Type
article
Source
Biophysical Journal. 118(11)
Subject
Biological Sciences
Genetics
Chlamydomonas
Diffusion
Flagella
Kinesins
Protein Transport
Physical Sciences
Chemical Sciences
Biophysics
Biological sciences
Chemical sciences
Physical sciences
Language
Abstract
Flagellar length control in Chlamydomonas is a tractable model system for studying the general question of organelle size regulation. We have previously proposed that the diffusive return of the kinesin motor that powers intraflagellar transport can play a key role in length regulation. Here, we explore how the motor speed and diffusion coefficient for the return of kinesin-2 affect flagellar growth kinetics. We find that the system can exist in two distinct regimes, one dominated by motor speed and one by diffusion coefficient. Depending on length, a flagellum can switch between these regimes. Our results indicate that mutations can affect the length in distinct ways. We discuss our theory's implication for flagellar growth influenced by beating and provide possible explanations for the experimental observation that a beating flagellum is usually longer than its immotile mutant. These results demonstrate how our simple model can suggest explanations for mutant phenotypes.