Journal Article

An Essential Role for DYF-11/MIP-T3 in Assembling Functional Intraflagellar Transport Complexes

Leitch, Carmen C., Héon, Elise, Davis, Erica E., Katsanis, Nicholas, Li, Chunmei, Zhen, Mei, Inglis, Peter N., Swoboda, Peter, Efimenko, Evgeni, Leroux, Michel R., Mok, Calvin A., Zaghloul, Norann A., Bialas, Nathan J., Healey, Michael P.

2008

Overview

MIP-T3 is a human protein found previously to associate with microtubules and the kinesin-interacting neuronal protein DISC1 (Disrupted-in-Schizophrenia 1), but whose cellular function(s) remains unknown. Here we demonstrate that the C. elegans MIP-T3 ortholog DYF-11 is an intraflagellar transport (IFT) protein that plays a critical role in assembling functional kinesin motor-IFT particle complexes. We have cloned a loss of function dyf-11 mutant in which several key components of the IFT machinery, including Kinesin-II, as well as IFT subcomplex A and B proteins, fail to enter ciliary axonemes and/or mislocalize, resulting in compromised ciliary structures and sensory functions, and abnormal lipid accumulation. Analyses in different mutant backgrounds further suggest that DYF-11 functions as a novel component of IFT subcomplex B. Consistent with an evolutionarily conserved cilia-associated role, mammalian MIP-T3 localizes to basal bodies and cilia, and zebrafish mipt3 functions synergistically with the Bardet-Biedl syndrome protein Bbs4 to ensure proper gastrulation, a key cilium- and basal body-dependent developmental process. Our findings therefore implicate MIP-T3 in a previously unknown but critical role in cilium biogenesis and further highlight the emerging role of this organelle in vertebrate development.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Animals / Animals, Genetically Modified / Base Sequence / Biological Transport, Active / Biosynthesis / Caenorhabditis elegans - genetics / Caenorhabditis elegans - growth & development / Caenorhabditis elegans - physiology / Caenorhabditis elegans Proteins - chemistry / Caenorhabditis elegans Proteins - genetics / Caenorhabditis elegans Proteins - physiology / Cell Biology/Cytoskeleton / Cell division / Cilia - physiology / Danio rerio / Developmental Biology/Developmental Molecular Mechanisms / DNA Primers - genetics / DNA, Helminth - genetics / Embryos / Evacuations & rescues / Flagella - physiology / Genes, Helminth / Genetics / Genetics and Genomics / Humans / Intracellular Signaling Peptides and Proteins - chemistry / Intracellular Signaling Peptides and Proteins - genetics / Intracellular Signaling Peptides and Proteins - physiology / Medical research / Microtubule-Associated Proteins - chemistry / Microtubule-Associated Proteins - genetics / Microtubule-Associated Proteins - physiology / Morphogenesis / Motility / Multiprotein Complexes / Mutation / Nematodes / Neurons, Afferent - physiology / Organisms / Phenotype / Proteins / Signal Transduction