Eukaryotic Cell doi:10.1128/EC.00341-07
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
A novel 44-kDa subunit of axonemal dynein conserved from Chlamydomonas to mammals
Ryosuke Yamamoto,
Haru-aki Yanagisawa,
Toshiki Yagi,
and
Ritsu Kamiya*
Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan and CREST, Japan Science and Technology Corporation, Japan
* To whom correspondence should be addressed. Email:
kamiyar{at}biol.s.u-tokyo.ac.jp.
 |
Abstract |
|---|
Cilia and flagella have multiple dyneins in their inner and outer arms. Chlamydomonas inner-arm dynein contains at least seven major subspecies (dynein a-g), of which all but dynein f (also called dynein I1) are the single-headed type that are composed of a single heavy chain, actin, and either centrin or a 28 kDa protein (p28). Dynein d was found to associate with two additional proteins of 38 kDa (p38) and 44 kDa (p44). Following the characterization of the p38 protein (24), we have identified the 44-kDa protein (p44) to be a novel component of dynein d using an immuno-precipitation approach. p44 is present along the length of the axonemes and is diminished, but not absent, in the mutants ida4 and ida5, both lacking this dynein. In the ida5 axoneme, p44 and p38 appear to form a complex, suggesting that they constitute the docking site of dynein d on the outer doublet. p44 has potential homologues in other ciliated organisms. For example, the mouse homologue of p44, NYD-SP14, was found to be strongly expressed in tissues with motile cilia and flagella. These results suggest that inner arm dynein d and its subunit organization are widely conserved.
