The intraflagellar transport protein, IFT88, is essential for vertebrate photoreceptor assembly and maintenance.
Approximately 10% of the photoreceptor outer segment (OS) is turned over each day, requiring large amounts of lipid and protein to be moved from the inner segment to the OS. Defects in intraphotoreceptor transport can lead to retinal degeneration and blindness. The transport mechanisms are unknown, but because the OS is a modified cilium, intraflagellar transport (IFT) is a candidate mechanism. IFT involves movement of large protein complexes along ciliary microtubules and is required for assembly and maintenance of cilia. We show that IFT particle proteins are localized to photoreceptor connecting cilia. We further find that mice with a mutation in the IFT particle protein gene, Tg737/IFT88, have abnormal OS development and retinal degeneration. Thus, IFT is important for assembly and maintenance of the vertebrate OS.
Pazour
Gregory J
GJ
Department of Cell Biology, University of Massachusetts Medical School, Worcester, MA 01655, USA.
Baker
Sheila A
SA
Deane
James A
JA
Cole
Douglas G
DG
Dickert
Bethany L
BL
Rosenbaum
Joel L
JL
Witman
George B
GB
Besharse
Joseph C
JC
D000818:Animals; D001766:Blindness / Q000209:etiology; D002417:Cattle; D002696:Chlamydomonas; D002923:Cilia / Q000737:chemistry / Q000378:metabolism; D005407:Flagella / Q000378:metabolism; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional / Q000502:physiology; D010940:Plant Proteins; D011506:Proteins / Q000235:genetics; D015800:Protozoan Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits; D017948:Retinal Rod Photoreceptor Cells / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism*; D017299:Rod Opsins / Q000378:metabolism; D013737:Testis / Q000737:chemistry; D022161:Transport Vesicles / Q000737:chemistry / Q000378:metabolism; D025521:Tumor Suppressor Proteins
C416363:IFT88 protein, Chlamydomonas; D010940:Plant Proteins; D011506:Proteins; D015800:Protozoan Proteins; D017299:Rod Opsins; C490898:Tg737Rpw protein, mouse; D025521:Tumor Suppressor Proteins