The cotton kinesin-like calmodulin-binding protein associates with cortical microtubules in cotton fibers.
Microtubules in interphase plant cells form a cortical array, which is critical for plant cell morphogenesis. Genetic studies imply that the minus end-directed microtubule motor kinesin-like calmodulin-binding protein (KCBP) plays a role in trichome morphogenesis in Arabidopsis. However, it was not clear whether this motor interacted with interphase microtubules. In cotton (Gossypium hirsutum) fibers, cortical microtubules undergo dramatic reorganization during fiber development. In this study, cDNA clones of the cotton KCBP homolog GhKCBP were isolated from a cotton fiber-specific cDNA library. During cotton fiber development from 10 to 21 DPA, the GhKCBP protein level gradually decreases. By immunofluorescence, GhKCBP was detected as puncta along cortical microtubules in fiber cells of different developmental stages. Thus our results provide evidence that GhKCBP plays a role in interphase cell growth likely by interacting with cortical microtubules. In contrast to fibers, in dividing cells of cotton, GhKCBP localized to the nucleus, the microtubule preprophase band, mitotic spindle, and the phragmoplast. Therefore KCBP likely exerts multiple roles in cell division and cell growth in flowering plants.
Section of Plant Biology, University of California, One Shields Avenue, Davis 95616, USA.
Mary L
ML
Preuss
Deborah P
DP
Delmer
Bo
B
Liu
D000595:Amino Acid Sequence; D002148:Calmodulin-Binding Proteins / Q000378:metabolism; D002455:Cell Division / Q000235:genetics; D032561:Cotton Fiber; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D003368:Gossypium / Q000235:genetics / Q000378:metabolism*; D016547:Kinesins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008869:Microtubule-Associated Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA
D002148:Calmodulin-Binding Proteins; D018076:DNA, Complementary; D008869:Microtubule-Associated Proteins; D010940:Plant Proteins; D016547:Kinesins