Type of Submission
Poster
Keywords
Tetrahymena, kinetodesmal fiber, centrin, laminin
Proposal
Tetrahymena thermophila are free-living ciliated organisms belonging to Kingdom Protista. These organisms possess large numbers of cilia that are used for feeding as well as locomotion. The cilia are attached to microtubule organizing centers (MTOC) called basal bodies, which are rich in centrin, a calcium binding protein present in MTOCs. Because of the mechanical stress that ciliary beating puts on the plasma membrane, these cells have kinetodesmal fibers, composed of bundled coiled-coil proteins which grow from the proximal end of the basal bodies and stabilize the plasma membrane.
Laminin is a cross-linking protein found in the extracellular matrix of animals. Using an antibody against laminin-b1, we found that the antibody localized to kinetodesmal fibers which overlapped the basal bodies stained by the anti-centrin antibody. To determine whether these proteins were in the same complex, we did co-immunoprecipitation using both our anti-centrin and anti-laminin antibodies. Both antibodies precipitated centrin (a doublet at 20 kD) as well as a number of presumed laminin-like proteins between 37 and 50 kD. We also found a number of laminin homologues in the Tetrahymena Genome Database. Further studies will be needed to determine which of these putative proteins is present in the kinetodesmal fiber.
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Characterization of a Laminin-like Protein in the Kinetodesmal Fibers of Tetrahymena thermophila
Tetrahymena thermophila are free-living ciliated organisms belonging to Kingdom Protista. These organisms possess large numbers of cilia that are used for feeding as well as locomotion. The cilia are attached to microtubule organizing centers (MTOC) called basal bodies, which are rich in centrin, a calcium binding protein present in MTOCs. Because of the mechanical stress that ciliary beating puts on the plasma membrane, these cells have kinetodesmal fibers, composed of bundled coiled-coil proteins which grow from the proximal end of the basal bodies and stabilize the plasma membrane.
Laminin is a cross-linking protein found in the extracellular matrix of animals. Using an antibody against laminin-b1, we found that the antibody localized to kinetodesmal fibers which overlapped the basal bodies stained by the anti-centrin antibody. To determine whether these proteins were in the same complex, we did co-immunoprecipitation using both our anti-centrin and anti-laminin antibodies. Both antibodies precipitated centrin (a doublet at 20 kD) as well as a number of presumed laminin-like proteins between 37 and 50 kD. We also found a number of laminin homologues in the Tetrahymena Genome Database. Further studies will be needed to determine which of these putative proteins is present in the kinetodesmal fiber.
