Biomaterial Database

The cilium secretes bioactive ectosomes. 2013

Christopher R Wood, and Kaiyao Huang, and Dennis R Diener, and Joel L Rosenbaum

Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA.

The release of membrane vesicles from the surface of cells into their surrounding environment is now recognized as an important pathway for the delivery of proteins to extracellular sites of biological function. Membrane vesicles of this kind, termed exosomes and ectosomes, are the result of active processes and have been shown to carry a wide array of biological effector molecules that can play roles in cell-to-cell communication and remodeling of the extracellular space. Degradation of the extracellular matrix (ECM) through the regulated release of proteolytic enzymes is a key process for development, morphogenesis, and cell migration in animal and plant cells. Here we show that the unicellular alga Chlamydomonas achieves the timely degradation of its mother cell wall, a type of ECM, through the budding of ectosomes directly from the membranes of its flagella. Using a combination of immunoelectron microscopy, immunofluorescence microscopy, and functional analysis, we demonstrate that these vesicles, which we term ciliary ectosomes, act as carriers of the proteolytic enzyme necessary for the liberation of daughter cells following mitosis. Chlamydomonas has proven to be the key unicellular model for the highly conserved mechanisms of mammalian cilia, and our results suggest that cilia may be an underappreciated source of bioactive, extracellular membrane vesicles.

UI	MeSH Term	Description	Entries
D008856	Microscopy, Fluorescence	Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.	Fluorescence Microscopy,Immunofluorescence Microscopy,Microscopy, Immunofluorescence,Fluorescence Microscopies,Immunofluorescence Microscopies,Microscopies, Fluorescence,Microscopies, Immunofluorescence
D010447	Peptide Hydrolases	Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.	Peptidase,Peptidases,Peptide Hydrolase,Protease,Proteases,Proteinase,Proteinases,Proteolytic Enzyme,Proteolytic Enzymes,Esteroproteases,Enzyme, Proteolytic,Hydrolase, Peptide
D002696	Chlamydomonas	A genus GREEN ALGAE in the order VOLVOCIDA. It consists of solitary biflagellated organisms common in fresh water and damp soil.	Chlamydomona
D002923	Cilia	Populations of thin, motile processes found covering the surface of ciliates (CILIOPHORA) or the free surface of the cells making up ciliated EPITHELIUM. Each cilium arises from a basic granule in the superficial layer of CYTOPLASM. The movement of cilia propels ciliates through the liquid in which they live. The movement of cilia on a ciliated epithelium serves to propel a surface layer of mucus or fluid. (King & Stansfield, A Dictionary of Genetics, 4th ed)	Motile Cilia,Motile Cilium,Nodal Cilia,Nodal Cilium,Primary Cilia,Primary Cilium,Cilium,Cilia, Motile,Cilia, Nodal,Cilia, Primary,Cilium, Motile,Cilium, Nodal,Cilium, Primary
D005109	Extracellular Matrix	A meshwork-like substance found within the extracellular space and in association with the basement membrane of the cell surface. It promotes cellular proliferation and provides a supporting structure to which cells or cell lysates in culture dishes adhere.	Matrix, Extracellular,Extracellular Matrices,Matrices, Extracellular
D016253	Microscopy, Immunoelectron	Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.	Immunoelectron Microscopy,Microscopy, Immuno-Electron,Immuno-Electron Microscopies,Immuno-Electron Microscopy,Immunoelectron Microscopies,Microscopies, Immuno-Electron,Microscopies, Immunoelectron,Microscopy, Immuno Electron
D055252	Cell-Derived Microparticles	Extracellular vesicles generated by the shedding of CELL MEMBRANE blebs.	Cell Membrane Microparticles,Circulating Cell-Derived Microparticles,Ectosomes,Microparticles, Cell-Derived,Shedding Microvesicles,Cell Derived Microparticles,Cell Membrane Microparticle,Cell-Derived Microparticle,Cell-Derived Microparticle, Circulating,Cell-Derived Microparticles, Circulating,Circulating Cell Derived Microparticles,Circulating Cell-Derived Microparticle,Ectosome,Membrane Microparticle, Cell,Membrane Microparticles, Cell,Microparticle, Cell Membrane,Microparticle, Cell-Derived,Microparticle, Circulating Cell-Derived,Microparticles, Cell Derived,Microparticles, Cell Membrane,Microparticles, Circulating Cell-Derived,Microvesicle, Shedding,Microvesicles, Shedding,Shedding Microvesicle
D059748	Proteolysis	Cleavage of proteins into smaller peptides or amino acids either by PROTEASES or non-enzymatically (e.g., Hydrolysis). It does not include Protein Processing, Post-Translational.	Protein Degradation,Protein Digestion,Degradation, Protein,Degradations, Protein,Digestion, Protein,Digestions, Protein,Protein Degradations,Protein Digestions,Proteolyses