scholarly journals Experimental and statistical post-validation of positive example EST sequences carrying peroxisome targeting signals type 1 (PTS1)

2012 ◽  
Vol 7 (2) ◽  
pp. 263-268 ◽  
Author(s):  
Thomas Lingner ◽  
Amr R. A. Kataya ◽  
Sigrun Reumann
Keyword(s):  
Targeting Signals ◽  
Peroxisome Targeting Signals

Evidence for a novel pathway for the targeting of a Saccharomyces cerevisiae peroxisomal protein belonging to the isomerase/hydratase family

2000 ◽  
Vol 113 (3) ◽  
pp. 533-544
Author(s):  
I.V. Karpichev ◽  
G.M. Small
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Beta Oxidation ◽  
Peroxisomal Protein ◽  
Intracellular Targeting ◽  
Targeting Signals ◽  
Peroxisome Targeting Signals

We, and others, have identified a novel Saccharomyces cerevisiae peroxisomal protein that belongs to the isomerase/hydratase family. The protein, named Dci1p, shares 50% identity with Eci1p, a delta(3)-cis-delta(2)-trans-enoyl-CoA isomerase that acts as an auxiliary enzyme in the beta-oxidation of unsaturated fatty acids. Both of these proteins are localized to peroxisomes, and both contain motifs at their amino- and carboxyl termini that resemble peroxisome targeting signals (PTS) 1 and 2. However, we demonstrate that the putative type 1 signaling motif is not required for the peroxisomal localization of either of these proteins. Furthermore, the correct targeting of Eci1p and Dci1p occurs in the absence of the receptors for the type 1 or type 2 peroxisome targeting pathway. Together, these data suggest a novel mechanism for the intracellular targeting of these peroxisomal proteins.

scholarly journals Identification of two novel type 1 peroxisomal targeting signals in Arabidopsis thaliana

2014 ◽  
Vol 116 (8) ◽  
pp. 1307-1312 ◽  
Author(s):  
Rigoberto A. Ramirez ◽  
Brian Espinoza ◽  
Ernest Y. Kwok
Keyword(s):  
Arabidopsis Thaliana ◽  
Peroxisomal Targeting ◽  
Targeting Signals

scholarly journals Interdependence of the Peroxisome-targeting Receptors in Arabidopsis thaliana: PEX7 Facilitates PEX5 Accumulation and Import of PTS1 Cargo into Peroxisomes

2010 ◽  
Vol 21 (7) ◽  
pp. 1263-1271 ◽  
Author(s):  
Naxhiely Martínez Ramón ◽  
Bonnie Bartel
Keyword(s):  
Arabidopsis Thaliana ◽  
Green Fluorescent Protein ◽  
Protein Import ◽  
Fluorescent Protein ◽  
Protein Accumulation ◽  
Animal Development ◽  
Metabolic Reactions ◽  
Targeting Signals ◽  
Green Fluorescent ◽  
Peroxisome Targeting Signals

Peroxisomes compartmentalize certain metabolic reactions critical to plant and animal development. The import of proteins from the cytosol into the organelle matrix depends on more than a dozen peroxin (PEX) proteins, with PEX5 and PEX7 serving as receptors that shuttle proteins bearing one of two peroxisome-targeting signals (PTSs) into the organelle. PEX5 is the PTS1 receptor; PEX7 is the PTS2 receptor. In plants and mammals, PEX7 depends on PEX5 binding to deliver PTS2 cargo into the peroxisome. In this study, we characterized a pex7 missense mutation, pex7-2, that disrupts both PEX7 cargo binding and PEX7-PEX5 interactions in yeast, as well as PEX7 protein accumulation in plants. We examined localization of peroxisomally targeted green fluorescent protein derivatives in light-grown pex7 mutants and observed not only the expected defects in PTS2 protein import but also defects in PTS1 import. These PTS1 import defects were accompanied by reduced PEX5 accumulation in light-grown pex7 seedlings. Our data suggest that PEX5 and PTS1 import depend on the PTS2 receptor PEX7 in Arabidopsis and that the environment may influence this dependence. These data advance our understanding of the biogenesis of these essential organelles and provide a possible rationale for the retention of the PTS2 pathway in some organisms.

Crystalloid Inclusions in Hepatocyte Mitochondria and Their Similarity to Cytoplasmic Crystalloids

1974 ◽  
Vol 32 ◽  
pp. 198-199
Author(s):  
Odell T. Minick ◽  
Hidejiro Yokoo
Keyword(s):  
Liver Disease ◽  
Alcoholic Liver Disease ◽  
Special Interest ◽  
Structural Variations ◽  
Mitochondrial Alterations ◽  
The Matrix ◽  
Crystalloid Inclusions ◽  
Liver Biopsies

Mitochondrial alterations were studied in 25 liver biopsies from patients with alcoholic liver disease. Of special interest were the morphologic resemblance of certain fine structural variations in mitochondria and crystalloid inclusions. Four types of alterations within mitochondria were found that seemed to relate to cytoplasmic crystalloids.Type 1 alteration consisted of localized groups of cristae, usually oriented in the long direction of the organelle (Fig. 1A). In this plane they appeared serrated at the periphery with blind endings in the matrix. Other sections revealed a system of equally-spaced diagonal lines lengthwise in the mitochondrion with cristae protruding from both ends (Fig. 1B). Profiles of this inclusion were not unlike tangential cuts of a crystalloid structure frequently seen in enlarged mitochondria described below.

Evidence for a shear mechanism for the precipitation of γ-zirconium hydride in zirconium

1978 ◽  
Vol 36 (1) ◽  
pp. 658-659
Author(s):  
G.J.C. Carpenter
Keyword(s):  
Elevated Temperature ◽  
Strain Field ◽  
Zirconium Hydride ◽  
Zirconium Atom ◽  
Atom Diffusion ◽  
Solvus Temperature ◽  
Hexagonal Close Packed ◽  
Partial Dislocations ◽  
The Face

In zirconium-hydrogen alloys, rapid cooling from an elevated temperature causes precipitation of the face-centred tetragonal (fct) phase, γZrH, in the form of needles, parallel to the close-packed <1120>zr directions (1). With low hydrogen concentrations, the hydride solvus is sufficiently low that zirconium atom diffusion cannot occur. For example, with 6 μg/g hydrogen, the solvus temperature is approximately 370 K (2), at which only the hydrogen diffuses readily. Shears are therefore necessary to produce the crystallographic transformation from hexagonal close-packed (hep) zirconium to fct hydride.The simplest mechanism for the transformation is the passage of Shockley partial dislocations having Burgers vectors (b) of the type 1/3<0110> on every second (0001)Zr plane. If the partial dislocations are in the form of loops with the same b, the crosssection of a hydride precipitate will be as shown in fig.1. A consequence of this type of transformation is that a cumulative shear, S, is produced that leads to a strain field in the surrounding zirconium matrix, as illustrated in fig.2a.

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