Back to Search
Start Over
Chlamydomonas DYX1C1/PF23 is essential for axonemal assembly and proper morphology of inner dynein arms
- Source :
- PLoS Genetics, Vol 13, Iss 9, p e1006996 (2017), PLoS Genetics
- Publication Year :
- 2017
- Publisher :
- Public Library of Science (PLoS), 2017.
-
Abstract
- Cytoplasmic assembly of ciliary dyneins, a process known as preassembly, requires numerous non-dynein proteins, but the identities and functions of these proteins are not fully elucidated. Here, we show that the classical Chlamydomonas motility mutant pf23 is defective in the Chlamydomonas homolog of DYX1C1. The pf23 mutant has a 494 bp deletion in the DYX1C1 gene and expresses a shorter DYX1C1 protein in the cytoplasm. Structural analyses, using cryo-ET, reveal that pf23 axonemes lack most of the inner dynein arms. Spectral counting confirms that DYX1C1 is essential for the assembly of the majority of ciliary inner dynein arms (IDA) as well as a fraction of the outer dynein arms (ODA). A C-terminal truncation of DYX1C1 shows a reduction in a subset of these ciliary IDAs. Sucrose gradients of cytoplasmic extracts show that preassembled ciliary dyneins are reduced compared to wild-type, which suggests an important role in dynein complex stability. The role of PF23/DYX1C1 remains unknown, but we suggest that DYX1C1 could provide a scaffold for macromolecular assembly.<br />Author summary Most animal cells have antenna-like organelles called “cilia”. These organelles have various important functions both in motility and sensing the environment. Motile cilia are essential for moving cells as well as moving fluids across a surface. The waveform of motile cilia requires large macromolecular motors; these are the ciliary dyneins. These dynein complexes are assembled in the cytoplasm in a pathway called preassembly, and then transported into cilia. Defects in this process cause a heterogeneous human disease called primary ciliary dyskinesia that results, for example, in the disruption of the motility of respiratory tract cilia, sperm and nodal cilia during development. The mechanisms of the preassembly pathway are not fully understood. In this study, we use a mutation in the well-conserved DYX1C1/PF23 gene of the green alga, Chlamydomonas reinhardtii. Loss of a conserved domain (DYX) reveals a failure to assemble most ciliary dyneins. Preassembly of inner arm dyneins is particularly affected. We find that if dynein arms are not assembled, dynein subunits in the cytoplasm are unstable. We suggest that DYX1C1 may play a role as a scaffold for other preassembly factors and the dynein subunits.
- Subjects :
- 0301 basic medicine
Cytoplasm
Cancer Research
Mutant
Biochemistry
Database and Informatics Methods
0302 clinical medicine
Cytoskeleton
Genetics (clinical)
Protozoans
Cilium
Microtubule Motors
Eukaryota
Cell biology
Macromolecular assembly
Cellular Structures and Organelles
Sequence Analysis
Research Article
Trypanosoma
lcsh:QH426-470
Bioinformatics
Motor Proteins
Immunoblotting
Dynein
Molecular Probe Techniques
macromolecular substances
Biology
Research and Analysis Methods
Motor protein
03 medical and health sciences
Protein Domains
Molecular Motors
Sequence Motif Analysis
Genetics
Cilia
Molecular Biology Techniques
Molecular Biology
Ecology, Evolution, Behavior and Systematics
Chlamydomonas
Organisms
Biology and Life Sciences
Proteins
Dyneins
Cell Biology
biology.organism_classification
Parasitic Protozoans
Cytoskeletal Proteins
lcsh:Genetics
030104 developmental biology
030217 neurology & neurosurgery
Subjects
Details
- Language :
- English
- ISSN :
- 15537404 and 15537390
- Volume :
- 13
- Issue :
- 9
- Database :
- OpenAIRE
- Journal :
- PLoS Genetics
- Accession number :
- edsair.doi.dedup.....4cd74d15f2c2f35a27c9da35a5805823