The Kinases LF4 and CNK2 Control Ciliary Length by Feedback Regulation of Assembly and Disassembly Rates

作者：Hilton Laura K; Gunawardane Kavisha; Kim Joo Wan; Schwarz Marianne C; Quarmby Lynne M^*

来源：Current Biology, 2013, 23(22): 2208-2214.

DOI：10.1016/j.cub.2013.09.038

Background: Many of the diverse functions of cilia depend upon tight control of their length. Steady-state length reflects a balance between rates of ciliary assembly and disassembly, two parameters likely controlled by a length sensor of unknown identity or mechanism. %26lt;br%26gt;Results: A null mutation in Chlamydomonas CNK2, a member of the evolutionarily conserved family of NIMA-related kinases, reveals feedback regulation of assembly and disassembly rates. cnk2-1 mutant cells have a mild long-flagella (lf) phenotype as a consequence of reduced rates of flagellar disassembly. This is in contrast to the strong If mutant lf4-7, which exhibits an aberrantly high rate of assembly. Cells carrying both mutations have even longer flagella than lf4-7 single mutants do. In addition to their high rate of assembly, lf4-7 mutants have a CNK2-dependent increase in disassembly rate. Finally, cnk2-1 cells have a decreased rate of turnover of flagellar sub-units at the tip of the flagellum, demonstrating that the effects on disassembly are compensated by a reduced rate of assembly. %26lt;br%26gt;Conclusions: We propose a model wherein CNK2 and LF4 modulate rates of disassembly and assembly respectively in a feedback loop that is activated when flagella exceed optimal length.

• 出版日期2013-11-18