We have produced hybrid liposomes (HL) which can be prepared by sonication of a mixture of vesicular and micellar molecules in a buffer solution. Some interesting results are as follows; HL remarkably inhibited the growth of cancer cells along with apoptosis in vitro and in vivo. Anticancer effects increased with a growth in membrane fluidity of HL and fluidity of plasma membranes of cancer cells. In clinical applications, prolonged survival and remarkable reduction of neoplasm were attained in patients with lymphoma after the treatment with HL without any side effects after the approval of the bioethics committee.
Magnetosomes synthesized in magnetotactic bacteria function as a cellular compass to navigate along the Earth’s magnetic field. The magnetosome contains various types of specific associated proteins. Most of the magnetosome-associated proteins are encoded in gene clusters within a genetic “magnetosome island,” which is essential for the synthesis of magnetosomes. Our atomic force microscopy studies indicated that the thickness of the organic layer wrapped around the magnetite crystal was ~7 nm, and magnetosome-associated protein MamA was localized at the surface of the organic layer. In this review we present recent progress on “Structure and Function of Magnetosomes” and propose the structural model of magnetosomes in the cell.
During synaptic transmission, exocytosis and endocytosis of synaptic vesicles must be balanced for maintaining the number of releasable vesicles. We found that protein kinase G (PKG) plays this balancing role at the calyx of Held presynaptic terminals when glutamate is massively released by exocytosis. Glutamate increases postsynaptic NO via Ca2+ influx through NMDA receptors, and NO retrogradely activates PKG. PKG activates RhoA/Rho-kinase, thereby elevating the PIP2 level that is critical for clathrin-mediated endocytosis. When this feedback cascade was inhibited, fidelity of neurotransmission was disrupted. We conclude that the exo-endocytic vesicle coupling supports high-fidelity high-frequency transmission at the fast central synapse.