Mutations in PIH proteins MOT48, TWI1 and PF13 define common and unique steps for preassembly of each, different ciliary dynein

by Ryosuke Yamamoto, Shiho Yanagi, Masahito Nagao, Yuya Yamasaki, Yui Tanaka, Winfield S. Sale, Toshiki Yagi, Takahide Kon

Ciliary dyneins are preassembled in the cytoplasm before being transported into cilia, and a family of proteins containing the PIH1 domain, PIH proteins, are involved in the assembly process. However, the functional differences and relationships between members of this family of proteins remain la rgely unknown. UsingChlamydomonas reinhardtii as a model, we isolated and characterized two novelChlamydomonas PIH preassembly mutants,mot48-2 andtwi1-1. A new allele ofmot48 (ida10),mot48-2, shows large defects in ciliary dynein assembly in the axoneme and altered motility. A second mutant,twi1-1, shows comparatively smaller defects in motility and dynein assembly. A double mutantmot48-2; twi1-1 displays greater reduction in motility and in dynein assembly compared to each single mutant. Similarly, a double mutanttwi1-1; pf13 also shows a significantly greater defect in motility and dynein assembly than either parent mutant. Thus, MOT48 (IDA10), TWI1 and PF13 may define different steps, and have partially overlapping functions, in a pathway required for ciliary dynein preassembly. Together, our data suggest the three PIH proteins function in preassembly steps that are both common and unique for different ciliary dyneins.

Source: PLoS Genetics - November 3, 2020 Category: Genetics & Stem Cells Authors: Ryosuke Yamamoto Source Type: research