title: Direct interactions of intraflagellar transport complex B proteins IFT88, IFT52, and IFT46.
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 approximately 500-kDa core that contains IFT88, 2x IFT81, 2x 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.
authors.affiliation: Department of Microbiology, Center for Reproductive Biology, University of Idaho, Moscow, Idaho 83844, USA.
authors.forename: Ben F
authors.initials: BF
authors.lastname: Lucker
authors.forename: Mark S
authors.initials: MS
authors.lastname: Miller
authors.forename: Slawomir A
authors.initials: SA
authors.lastname: Dziedzic
authors.forename: Philip T
authors.initials: PT
authors.lastname: Blackmarr
authors.forename: Douglas G
authors.initials: DG
authors.lastname: Cole
mesh_terms: D020418:Algal Proteins / Q000378:metabolism*; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism*; D016825:Chlamydomonas reinhardtii / Q000235:genetics / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000737:chemistry; D018274:Electroporation; D005407:Flagella / Q000378:metabolism*; D005786:Gene Expression Regulation; D008954:Models, Biological; D016296:Mutagenesis; D010641:Phenotype; D010940:Plant Proteins; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D015800:Protozoan Proteins / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry; D020798:Two-Hybrid System Techniques
chemical_list: D020418:Algal Proteins; D002352:Carrier Proteins; D003432:Cross-Linking Reagents; C416363:IFT88 protein, Chlamydomonas; D010940:Plant Proteins; D015800:Protozoan Proteins; D011994:Recombinant Proteins