Primary cilia are ubiquitous hair-like organelles, usually projecting from the cell surface. They are essential for the organogenesis and homeostasis of various physiological functions, and their dysfunction leads to a plethora of human diseases. However, there are few reports on the role of primary cilia in the immune system; therefore, we focused on their role in the thymus that nurtures immature lymphocytes to full-fledged T cells.
View Article and Find Full Text PDFLight-responsive regulation of ciliary motility is known to be conducted through modulation of dyneins, but the mechanism is not fully understood. Here, we report a novel subunit of the two-headed f/I1 inner arm dynein, named DYBLUP, in animal spermatozoa and a unicellular green alga. This subunit contains a BLUF (sensors of blue light using FAD) domain that appears to directly modulate dynein activity in response to light.
View Article and Find Full Text PDFMicroscopy (Oxf)
December 2020
Intracellular Ca(2+) induces ciliary reversal and backward swimming in Paramecium. However, it is not known how the Ca(2+) signal controls the motor machinery to induce ciliary reversal. We found that demembranated cilia on the ciliated cortical sheets from Paramecium caudatum lost the ability to undergo ciliary reversal after brief extraction with a solution containing 0.
View Article and Find Full Text PDFThe individual role of the outer dynein arm light chains in the molecular mechanisms of ciliary movements in response to second messengers, such as Ca(2+) and cyclic nucleotides, is unclear. We examined the role of the gene termed the outer dynein arm light chain 1 (LC1) gene of Paramecium tetraurelia (ODAL1), a homologue of the outer dynein arm LC1 gene of Chlamydomonas reinhardtii, in ciliary movements by RNA interference (RNAi) using a feeding method. The ODAL1-silenced (ODAL1-RNAi) cells swam slowly, and their swimming velocity did not increase in response to membrane-hyperpolarizing stimuli.
View Article and Find Full Text PDFThe paramagnetic microbead-based electrochemical binding assay was demonstrated for detecting two kinds of protein simultaneously. The principle of this assay is based on the sequestration electrochemistry. The protein binding electroactive magnetic microbeads which are conjugated with an electroactive compound and a ligand to bind specifically with a target protein were prepared.
View Article and Find Full Text PDFThe phosphoarginine shuttle system effectively regenerates ATP in the cilia of Paramecium caudatum. To estimate the effective concentration of ATP-regenerating enzymes, we attempted to reconstitute certain ATP-regenerating systems within the cilia of intact cortical sheets using exogenous enzymes and high-energy substances. The addition of phosphoenolpyruvate, which is one of the substrates in glycolysis, did not increase the ciliary beat frequency, whereas phosphocreatine together with exogenous creatine kinase, effectively increased the ciliary beat frequency.
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