Acetophenones were screened for activity against positive phototaxis of Chlamydomonas cells, a process that requires co-ordinated flagellar motility. The structure-activity relationships of a series of acetophenones are reported, including acetophenones that affect flagellar motility and cell viability. Notably, 4-methoxyacetophenone, 3,4-dimethoxyacetophenone, and 4-hydroxyacetophenone induced...

Specific effects of both in vivo activation and in vitro activation by cAMP-dependent phosphorylation on bending wave parameters of demembranated, reactivated, tunicate (Ciona intestinalis) and sea urchin (Lytechinus pictus) sperm flagella can be reversed by exposure to protein phosphatase. The effects of protein phosphatase incubation can be imitated by inclusion of LiCI in the reactivation so...

Flagellar glycoprotein synthesis and mobilization of flagellar glycoprotein pools have been followed during flagellar regeneration in Euglena. The glycosylation inhibitor tunicamycin has little effect on either regeneration kinetics or the complement of flagellar peptides as seen in SDS acrylamide gels, but tunicamycin totally inhibits incorporation of exogenously supplied [14C]xylose into flag...

Aeromonas spp. (gram-negative, aquatic bacteria which include enteropathogenic strains) have two distinct flagellar systems, namely a polar flagellum for swimming in liquid and multiple lateral flagella for swarming over surfaces. Only approximately 60% of mesophilic strains can produce lateral flagella. To evaluate flagellar contributions to Aeromonas intestinal colonization, we compared polar...

A mutant of Chlamydomonas reinhardtii with a variable number of flagella per cell has been used to investigate flagellar size control. The mutant and wild-type do not differ in cell size nor in flagellar length, yet the size of the intracellular pool of flagellar precursor protein can differ dramatically among individual mutant cells, with, for example, triflagellate cells having three times th...

FlhF proteins are putative GTPases that are often necessary for one or more steps in flagellar organelle development in polarly flagellated bacteria. In Campylobacter jejuni, FlhF is required for sigma(54)-dependent flagellar gene expression and flagellar biosynthesis, but how FlhF influences these processes is unknown. Furthermore, the GTPase activity of any FlhF protein and the requirement of...

The flagellar pocket is a bulb-like invagination of the plasma membrane that encloses the base of the single flagellum in trypanosomes. It is the site of all endo- and exocytic activity in the parasite and has thus been proposed to be a therapeutic target. At the neck of the flagellar pocket is an electron-dense cytoskeletal structure named the flagellar pocket collar. The protein BILBO1 was th...

Short Running Title: A model for trypanosome cell motility 2 Abstract: The eukaryotic flagellum is a complex and dynamic organelle that provides a cell with highly specialized functions. The flagellated protozoa are highly dependent on flagellar dynamics for environmental sensing, reproduction, cell morphology, and disease progression. Due to the functional diversity and structural nuances of t...

Flagella and cilia are structurally polarized organelles whose lengths are precisely defined, and alterations in length are related to several human disorders. Intraflagellar transport (IFT) and protein signaling molecules are implicated in specifying flagellar and ciliary length, but evidence has been lacking for a flagellum and cilium length sensor that could participate in active length cont...

Flagellar biogenesis in Helicobacter pylori involves the coordinated expression of flagellar genes with assembly of the flagellum. The H. pylori flagellar genes are organized into three regulons based on the sigma factor needed for their transcription (RpoD [σ(80)], RpoN [σ(54)], or FliA [σ(28)]). Transcription of RpoN-dependent genes is activated by a two-component system consisting of the sen...