Peroxisomes of higher eukaryotes, glycosomes of kinetoplastids, & glyoxysomes of plants are related microbody organelles that perform differing metabolic functions tailored to their cellular environments. The close evolutionary relationship of these organelles is most clearly evidenced by the conservation of proteins involved in matrix protein import and biogenesis.
glycosome can be viewed as an offshoot of the peroxisomal lineage with additional metabolic functions, specifically glycolysi - [Read Biogenesis and Function of Peroxisomes and Glycosomes]
Acidocalcisomes, the dense acidic calcium-storing organelles, which were originally identified in Trypanosoma cruzi, have no parallels in mammalian cells. They thus represent a unique functional characteristic, not shared by the host and hence offer an important potential target for chemotherapy of Chagas disease. - [Read Fractionation of Acidocalcisomes and Other Organelles from Trypanosoma, Leishmania, Chlamydomonas]
Generally in iodixanol gradients the density of organelles decreases in the series: peroxisomes, mitochondria, lysosomes, ER, Golgi, although in Dictyostelium discoideum, the lysosomes are denser than the mitochondria. Iodixanol gradients can usually provide satisfactory resolution of all these membrane particles although it may be necessary to modulate either the gradient or centrifugation parameters in order to optimize a particular separation. - [Read Fractionation of Mitochondria, Lysosomes, Peroxisomes, ER and Golgi in Pre-formed Iodixanol Gradient]
Using confocal laser-scanning microscope & GFP fusion proteins in time-lapse imaging to visualize the behavior of organelles and to track membrane-bound transport intermediates that bud off from organelles. Practical issues related to construction & expression of GFP fusion proteins are discussed. Essential for optimizing the brightness and expression levels of GFP fusion proteins so that intracellular membrane-bound structures containing these fusion proteins can be readily visualized. - [Read Imaging of Organelle Membrane Systems and Membrane Traffic in Living Cells]
Describes two methods for using the immunoperoxidase reaction to localize antigens at the electron microscope level; one for adherent cultured cells and one for tissue sections. The reaction conditions are first optimized at the light microscope level and then adapted for EM level observation. These methods allow for reliable detection of antigens at the cell surface, within the cell, and especially in membrane bounded organelles. - [Read Immunoperoxidase Methods for Localization of Antigens in Cultured Cells and Tissues]
The physiological reactions of mitochondria and chloroplasts can be reduced to a series of electron transfers, catalyzed by specific enzymes found within the organelles. Thus, we can study the component processes of photosynthesis and respiration by isolating the organelles and measuring specific enzyme activity associated with that organelle. - [Read Photosynthesis and Respiration - Introduction]
This protocol uses a "light mitochondrial" pellet from a mammalian liver homogenate. The gradient thus has to resolve a variety of denser components (peroxisomes, lysosomes, mitochondria) from the Golgi membranes, which have a low density in iodixanol (1.06-1.09 g/ml) [1]. The protocol is
specifically tailored to the purification of Golgi membranes from this pellet and is unsuitable for the isolation or analysis of other organelles present in the light mitochondrial fraction. - [Read Purification of Golgi Membranes from a Light Mitochondrial Fraction in a Self-Generated Gradient]
This protocol describes a discontinuous gradient, which resolves the mitochondria from both lighter and denser organelles. Because the centrifugation is carried out for 4 h, diffusion will create a partially continuous gradient and this probably contributes to the resolution of the mitochondria from the lighter lysosomes. - [Read Purification of Mammalian Liver Mitochondria by Flotation Through a Pre-formed Discontinuous Iodixan]
Peroxisomes can be purified in self-generated iodixanol gradients in high yield (80-90%) with no detectable contamination from any other organelle. In iodixanol peroxisomes are the densest of the major subcellular organelles (ρ = 1.18-1.20 g/ml) present in the light mitochondrial fraction from
mammalian tissues and cells. - [Read Purification of Peroxisomes in a Self-Generated Gradient]
Peroxisomes can be purified in iodixanol gradients in high yield (80-90%) with no detectable contamination from any other organelle. This is a property unique to iodixanol because the
densities of other organelles, particularly that of mitochondria (approx ρ = 1.14 g/ml) and endoplasmic reticulum (approx ρ = 1.13 g/ml) are much lower than that of peroxisomes (approx ρ = 1.18 g/ml). - [Read Purification of Peroxisomes using a Density Barrier in a Swinging-Bucket Rotor]
Background and methods to study plant transport. Includes new methods to study protein trafficking in plant cells, includes: Identification of protein sorting pathways in non purified samples; Localization of organelle proteins by isotype tagging/isotype-coded affinity tag; Coupling of chemical genomics and proteomics; Top down mass spectrometry; Compartment-specific markers to aid in the purification of organelles. - [Read Understanding Protein Trafficking in Plant Cells Through Proteomics]