Title

DC3, the 21-kDa subunit of the outer dynein arm-docking complex (ODA-DC), is a novel EF-hand protein important for assembly of both the outer arm and the ODA-DC

GSBS Program

Biochemistry & Molecular Pharmacology

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Cell Biology; Program in Molecular Medicine

Date

9-16-2003

Document Type

Article

Medical Subject Headings

Amino Acid Sequence; Animals; Cell Movement; Chlamydomonas reinhardtii; Cloning, Molecular; Dynein ATPase; Flagella; Microscopy, Electron; Microtubules; Models, Molecular; Molecular Sequence Data; Mutation; Phylogeny; Protein Subunits; Protozoan Proteins; Sequence Alignment

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

The outer dynein arm-docking complex (ODA-DC) is a microtubule-associated structure that targets the outer dynein arm to its binding site on the flagellar axoneme (Takada et al. 2002. Mol. Biol. Cell 13, 1015-1029). The ODA-DC of Chlamydomonas contains three proteins, referred to as DC1, DC2, and DC3. We here report the isolation and sequencing of genomic and full-length cDNA clones encoding DC3. The sequence predicts a 21,341 Da protein with four EF-hands that is a member of the CTER (calmodulin, troponin C, essential and regulatory myosin light chains) group and is most closely related to a predicted protein from Plasmodium. The DC3 gene, termed ODA14, is intronless. Chlamydomonas mutants that lack DC3 exhibit slow, jerky swimming because of loss of some but not all outer dynein arms. Some outer doublet microtubules without arms had a "partial" docking complex, indicating that DC1 and DC2 can assemble in the absence of DC3. In contrast, DC3 cannot assemble in the absence of DC1 or DC2. Transformation of a DC3-deletion strain with the wild-type DC3 gene rescued both the motility phenotype and the structural defect, whereas a mutated DC3 gene was incompetent to rescue. The results indicate that DC3 is important for both outer arm and ODA-DC assembly.

Rights and Permissions

Citation: Mol Biol Cell. 2003 Sep;14(9):3650-63. Epub 2003 Jun 27. Link to article on publisher's site

Related Resources

Link to article in PubMed