ZFIN ID: ZDB-PUB-171109-10
Axonemal dynein assembly requires the R2TP complex component Pontin
Li, Y., Zhao, L., Yuan, S., Zhang, J., Sun, Z.
Date: 2017
Source: Development (Cambridge, England)   144(24): 4684-4693 (Journal)
Registered Authors: Sun, Zhaoxia
Keywords: Axonemal dynein arm, Cilia, Cytoplasmic foci, Dynein arm assembly, Pontin/Ruvbl1, Primary ciliary dyskinesia, R2TP, Reptin/Ruvbl2
MeSH Terms:
  • Animals
  • Axonemal Dyneins/genetics
  • Axonemal Dyneins/metabolism
  • Axoneme/metabolism*
  • Cilia/pathology
  • Cilia/physiology
  • DNA Helicases/genetics*
  • HSP90 Heat-Shock Proteins/metabolism
  • Male
  • Mice
  • Mice, Knockout
  • Movement
  • Nuclear Proteins/genetics*
  • Sperm Motility/genetics*
  • Zebrafish/embryology*
  • Zebrafish Proteins/genetics*
PubMed: 29113992 Full text @ Development
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ABSTRACT
Pontin (Ruvbl1) and Reptin (Ruvbl2) are closely related AAA ATPases. They are components of the Ruvbl1-Ruvbl2-Tah1-Pih1 (R2TP) complexes that function as co-chaperones for the assembly of multiple macromolecular protein complexes. Here, we show that Pontin is essential for cilia motility in both zebrafish and mouse and that Pontin and Reptin function cooperatively in this process. Zebrafish pontin mutants display phenotypes tightly associated with cilia defects, and cilia motility is lost in a number of ciliated tissues along with a reduction in the number of outer and inner dynein arms. Pontin protein is enriched in cytosolic puncta in ciliated cells in zebrafish embryos. In mouse testis, Pontin is essential for the stabilization of axonemal dynein intermediate chain 1 (DNAI1) and DNAI2, the first appreciated step in axonemal dynein arm assembly. Strikingly, multiple dynein arm assembly factors show structural similarities to either Tah1 or Pih1, the other two components of the R2TP complex. Based on these results, we propose that Pontin and Reptin function to facilitate dynein arm assembly in cytosolic foci enriched with R2TP-like complexes.
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