scholarly journals The DEG15 Serine Protease Cleaves Peroxisomal Targeting Signal 2-Containing Proteins in Arabidopsis

2008 ◽  
Vol 148 (4) ◽  
pp. 1847-1856 ◽  
Author(s):  
Holger Schuhmann ◽  
Pitter F. Huesgen ◽  
Christine Gietl ◽  
Iwona Adamska
Keyword(s):  
Serine Protease ◽  
Peroxisomal Targeting ◽  
Targeting Signal ◽  
Peroxisomal Targeting Signal

Dissection of the molecular mechanisms of protein targeting to the peroxisome using immunofluorescence and immunocryoelectron microscopies

1990 ◽  
Vol 48 (3) ◽  
pp. 44-45
Author(s):  
G-A. Keller ◽  
S. J. Gould ◽  
S. Subramani ◽  
S. Krisans
Keyword(s):  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Protein Targeting ◽  
Firefly Luciferase ◽  
Peroxisomal Enzyme ◽  
Transfected Cells ◽  
Peroxisomal Targeting ◽  
Targeting Signal ◽  
Series Of Experiments ◽  
Peroxisomal Targeting Signal

Subcellular compartments within eukaryotic cells must each be supplied with unique sets of proteins that must be directed to, and translocated across one or more membranes of the target organelles. This transport is mediated by cis- acting targeting signals present within the imported proteins. The following is a chronological account of a series of experiments designed and carried out in an effort to understand how proteins are targeted to the peroxisomal compartment.-We demonstrated by immunocryoelectron microscopy that the enzyme luciferase is a peroxisomal enzyme in the firefly lantern. -We expressed the cDNA encoding firefly luciferase in mammalian cells and demonstrated by immunofluorescence that the enzyme was transported into the peroxisomes of the transfected cells. -Using deletions, linker insertions, and gene fusion to identify regions of luciferase involved in its transport to the peroxisomes, we demonstrated that luciferase contains a peroxisomal targeting signal (PTS) within its COOH-terminal twelve amino acid.

Metabolic control of peroxisome abundance

1999 ◽  
Vol 112 (10) ◽  
pp. 1579-1590 ◽  
Author(s):  
C.C. Chang ◽  
S. South ◽  
D. Warren ◽  
J. Jones ◽  
A.B. Moser ◽  
...  
Keyword(s):  
Metabolic Control ◽  
Matrix Protein ◽  
Protein Import ◽  
Zellweger Syndrome ◽  
Mutant Gene ◽  
Peroxisomal Membrane ◽  
Peroxisomal Targeting ◽  
Targeting Signal ◽  
Complementation Groups ◽  
Peroxisomal Targeting Signal

Zellweger syndrome and related disorders represent a group of lethal, genetically heterogeneous diseases. These peroxisome biogenesis disorders (PBDs) are characterized by defective peroxisomal matrix protein import and comprise at least 10 complementation groups. The genes defective in seven of these groups and more than 90% of PBD patients are now known. Here we examine the distribution of peroxisomal membrane proteins in fibroblasts from PBD patients representing the seven complementation groups for which the mutant gene is known. Peroxisomes were detected in all PBD cells, indicating that the ability to form a minimal peroxisomal structure is not blocked in these mutants. We also observed that peroxisome abundance was reduced fivefold in PBD cells that are defective in the PEX1, PEX5, PEX12, PEX6, PEX10, and PEX2 genes. These cell lines all display a defect in the import of proteins with the type-1 peroxisomal targeting signal (PTS1). In contrast, peroxisome abundance was unaffected in cells that are mutated in PEX7 and are defective only in the import of proteins with the type-2 peroxisomal targeting signal. Interestingly, a fivefold reduction in peroxisome abundance was also observed for cells lacking either of two PTS1-targeted peroxisomal beta-oxidation enzymes, acyl-CoA oxidase and 2-enoyl-CoA hydratase/D-3-hydroxyacyl-CoA dehydrogenase. These results indicate that reduced peroxisome abundance in PBD cells may be caused by their inability to import these PTS1-containing enzymes. Furthermore, the fact that peroxisome abundance is influenced by peroxisomal 105-oxidation activities suggests that there may be metabolic control of peroxisome abundance.

Real time imaging reveals a peroxisomal reticulum in living cells

2000 ◽  
Vol 113 (20) ◽  
pp. 3663-3671 ◽  
Author(s):  
M. Schrader ◽  
S.J. King ◽  
T.A. Stroh ◽  
T.A. Schroer
Keyword(s):  
Real Time ◽  
Cytoplasmic Dynein ◽  
Living Cells ◽  
Real Time Imaging ◽  
Peroxisomal Targeting ◽  
Microtubule Motor ◽  
Targeting Signal ◽  
Peroxisomal Targeting Signal

We have directly imaged the dynamic behavior of a variety of morphologically different peroxisomal structures in HepG2 and COS-7 cells transfected with a construct encoding GFP bearing the C-terminal peroxisomal targeting signal 1. Real time imaging revealed that moving peroxisomes interacted with each other and were engaged in transient contacts, and at higher magnification, tubular peroxisomes appeared to form a peroxisomal reticulum. Local remodeling of these structures could be observed involving the formation and detachment of tubular processes that interconnected adjacent organelles. Inhibition of cytoplasmic dynein based motility by overexpression of the dynactin subunit, dynamitin (p50), inhibited the movement of peroxisomes in vivo and interfered with the reestablishment of a uniform distribution of peroxisomes after recovery from nocodazole treatment. Isolated peroxisomes moved in vitro along microtubules in the presence of a microtubule motor fraction. Our data reveal that peroxisomal behavior in vivo is significantly more dynamic and interactive than previously thought and suggest a role for the dynein/dynactin motor in peroxisome motility.

scholarly journals Expression of the Cymbidium Ringspot Virus 33-Kilodalton Protein in Saccharomyces cerevisiae and Molecular Dissection of the Peroxisomal Targeting Signal

2004 ◽  
Vol 78 (9) ◽  
pp. 4744-4752 ◽  
Author(s):  
Beatriz Navarro ◽  
Luisa Rubino ◽  
Marcello Russo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fluorescent Protein ◽  
Ringspot Virus ◽  
Intermediate Step ◽  
Cell Organelles ◽  
Peroxisomal Membrane ◽  
Essential Components ◽  
Peroxisomal Targeting ◽  
Targeting Signal ◽  
Peroxisomal Targeting Signal

ABSTRACT Open reading frame 1 in the viral genome of Cymbidium ringspot virus encodes a 33-kDa protein (p33), which was previously shown to localize to the peroxisomal membrane in infected and transgenic plant cells. To determine the sequence requirements for the organelle targeting and membrane insertion, the protein was expressed in the yeast Saccharomyces cerevisiae in native form (33K) or fused to the green fluorescent protein (33KGFP). Cell organelles were identified by immunolabeling of marker proteins. In addition, peroxisomes were identified by simultaneous expression of the red fluorescent protein DsRed containing a peroxisomal targeting signal and mitochondria by using the dye MitoTracker. Fluorescence microscopy showed the 33KGFP fusion protein concentrated in a few large bodies colocalizing with peroxisomes. These bodies were shown by electron microscopy to be composed by aggregates of peroxisomes, a few mitochondria and endoplasmic reticulum (ER) strands. In immunoelectron microscopy, antibodies to p33 labeled the peroxisomal clumps. Biochemical analysis suggested that p33 is anchored to the peroxisomal membrane through a segment of ca. 7 kDa, which corresponds to the sequence comprising two hydrophobic transmembrane domains and a hydrophilic interconnecting loop. Analysis of deletion mutants confirmed these domains as essential components of the p33 peroxisomal targeting signal, together with a cluster of three basic amino acids (KRR). In yeast mutants lacking peroxisomes p33 was detected in the ER. The possible involvement of the ER as an intermediate step for the integration of p33 into the peroxisomal membrane is discussed.

scholarly journals The Peroxisomal Targeting Signal 3 (PTS3) of the Budding Yeast Acyl-CoA Oxidase Is a Signal Patch

2020 ◽  
Vol 8 ◽  
Author(s):  
Błażej Kempiński ◽  
Anna Chełstowska ◽  
Jarosław Poznański ◽  
Kamil Król ◽  
Łukasz Rymer ◽  
...  
Keyword(s):  
Budding Yeast ◽  
Peroxisomal Targeting ◽  
Targeting Signal ◽  
Acyl Coa Oxidase ◽  
Peroxisomal Targeting Signal

scholarly journals The peroxin Pex17p of the yeast Yarrowia lipolytica is associated peripherally with the peroxisomal membrane and is required for the import of a subset of matrix proteins.

1997 ◽  
Vol 17 (5) ◽  
pp. 2511-2520 ◽  
Author(s):  
J J Smith ◽  
R K Szilard ◽  
M Marelli ◽  
R A Rachubinski
Keyword(s):  
Amino Acids ◽  
Oleic Acid ◽  
Yarrowia Lipolytica ◽  
Matrix Proteins ◽  
Peroxisomal Membrane ◽  
Peroxisomal Targeting ◽  
Targeting Signal ◽  
Carboxyl Terminal ◽  
Peroxisomal Targeting Signal ◽  
Yeast Yarrowia Lipolytica

PEX genes encode peroxins, which are required for the biogenesis of peroxisomes. The Yarrowia lipolytica PEX17 gene encodes the peroxin Pex17p, which is 671 amino acids in length and has a predicted molecular mass of 75,588 Da. Pex17p is peripherally associated with the peroxisomal membrane. The carboxyl-terminal tripeptide, Gly-Thr-Leu, of Pex17p is not necessary for its targeting to peroxisomes. Synthesis of Pex17p is low in cells grown in glucose-containing medium and increases after the cells are shifted to oleic acid-containing medium. Cells of the pex17-1 mutant, the original mutant strain, and the pex17-KA mutant, a strain in which most of the PEX17 gene is deleted, fail to form normal peroxisomes but instead contain numerous large, multimembraned structures. The import of peroxisomal matrix proteins in these mutants is selectively impaired. This selective import is not a function of the nature of the peroxisomal targeting signal. We suggest a regulatory role for Pex17p in the import of a subset of matrix proteins into peroxisomes.

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