Article

Direct interactions of intraflagellar transport complex B proteins IFT88, IFT52, and IFT46

Department of Microbiology, Center for Reproductive Biology, University of Idaho, Moscow, Idaho 83844, USA.
Journal of Biological Chemistry (Impact Factor: 4.57). 04/2010; 285(28):21508-18. DOI: 10.1074/jbc.M110.106997
Source: PubMed

ABSTRACT Intraflagellar transport (IFT) particles of Chlamydomonas reinhardtii contain two distinct protein complexes, A and B, composed of at least 6 and 15 protein subunits, respectively. As isolated
from C. reinhardtii flagella, IFT complex B can be further reduced to a ∼500-kDa core that contains IFT88, 2× IFT81, 2× IFT74/72, IFT52, IFT46,
IFT27, IFT25, and IFT22. In this study, yeast-based two-hybrid analysis was combined with bacterial coexpression to show that
three of the core B subunits, IFT88, IFT52, and IFT46, interact directly with each other and, together, are capable of forming
a ternary complex. Chemical cross-linking results support the IFT52-IFT88 interaction and provide additional evidence of an
association between IFT27 and IFT81. With previous studies showing that IFT81 and IFT74/72 interact to form a (IFT81)2(IFT74/72)2 heterotetramer and that IFT27 and IFT25 form a heterodimer, the architecture of complex B is revealing itself. Last, electroporation
of recombinant IFT46 was used to rescue flagellar assembly of a newly identified ift46 mutant and to monitor in vivo localization and movement of the IFT particles.

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