Biomaterial Database

Degradation of mistargeted OEE33 in the chloroplast stroma. 1996

T Halperin, and Z Adam

Department of Agricultural Botany, Faculty of Agriculture, Hebrew University, Rehovot, Israel.

OEE33, a component of the oxygen-evolving enzyme in chloroplasts, normally resides in the thylakoid lumen. In an attempt to study the fate of mistargeted proteins in chloroplasts, we substituted the bipartite transit peptide of OEE33 with that of CAB7, an integral thylakoid-membrane protein. As a result, when imported into isolated chloroplasts, the chimeric protein protein was targeted to the stroma instead of the thylakoid lumen. Whereas the wild-type OEE33 was totally stable for at least 2 h, the chimeric protein was rapidly degraded, with a half-life of 60 min. Degradation of the chimeric protein was stimulated by ATP supplementation. Degradation could also be observed in lysed chloroplasts, in an ATP-stimulated manner. When lysates were fractionated, the proteolytic activity was found to be associated mainly with the stromal fraction. This activity was very effectively inhibited by all tested inhibitors of serine proteases. Western blot analysis demonstrated that the stromal fraction active in degrading the chimeric OEE33 contains ClpC and ClpP, homologues of the regulatory and proteolytic subunits, respectively, of the bacterial, ATP-dependent, serine-type Clp protease.

UI	MeSH Term	Description	Entries
D010940	Plant Proteins	Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which PLANT PROTEINS, DIETARY is available.	Plant Protein,Protein, Plant,Proteins, Plant
D011993	Recombinant Fusion Proteins	Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.	Fusion Proteins, Recombinant,Recombinant Chimeric Protein,Recombinant Fusion Protein,Recombinant Hybrid Protein,Chimeric Proteins, Recombinant,Hybrid Proteins, Recombinant,Recombinant Chimeric Proteins,Recombinant Hybrid Proteins,Chimeric Protein, Recombinant,Fusion Protein, Recombinant,Hybrid Protein, Recombinant,Protein, Recombinant Chimeric,Protein, Recombinant Fusion,Protein, Recombinant Hybrid,Proteins, Recombinant Chimeric,Proteins, Recombinant Fusion,Proteins, Recombinant Hybrid
D002736	Chloroplasts	Plant cell inclusion bodies that contain the photosynthetic pigment CHLOROPHYLL, which is associated with the membrane of THYLAKOIDS. Chloroplasts occur in cells of leaves and young stems of plants. They are also found in some forms of PHYTOPLANKTON such as HAPTOPHYTA; DINOFLAGELLATES; DIATOMS; and CRYPTOPHYTA.	Chloroplast,Etioplasts,Etioplast
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D000251	Adenosine Triphosphatases	A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.	ATPases,Adenosinetriphosphatase,ATPase,ATPase, DNA-Dependent,Adenosine Triphosphatase,DNA-Dependent ATPase,DNA-Dependent Adenosinetriphosphatases,ATPase, DNA Dependent,Adenosinetriphosphatases, DNA-Dependent,DNA Dependent ATPase,DNA Dependent Adenosinetriphosphatases,Triphosphatase, Adenosine
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D012697	Serine Endopeptidases	Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.	Serine Endopeptidase,Endopeptidase, Serine,Endopeptidases, Serine
D049071	Endopeptidase Clp	An ATP-dependent protease found in prokaryotes, CHLOROPLASTS, and MITOCHONDRIA. It is a soluble multisubunit complex that plays a role in the degradation of many abnormal proteins.	ATP-Dependent Endoprotease Ti,Protease Ti,AAA(+) Chaperone ClpX,AAA(+) Unfoldase ClpX,Caseinolytic Peptidase B,Caseinolytic Peptidase B Protein Homolog,Clp Protease,ClpB Chaperone,ClpB Homolog,ClpX Chaperone,Hsp 78 Chaperone,Mitochondrial AAA ATPase Chaperonin,Ti Protease,ATP Dependent Endoprotease Ti,Chaperone, ClpB,Chaperone, ClpX,Chaperone, Hsp 78,Endoprotease Ti, ATP-Dependent,Peptidase B, Caseinolytic
D020418	Algal Proteins	Proteins found in any species of algae.	Algal Gene Product,Algal Gene Products,Algal Gene Protein,Algal Gene Proteins,Algal Peptide,Algal Peptides,Algal Protein,Gene Products, Algal,Gene Product, Algal,Gene Protein, Algal,Gene Proteins, Algal,Peptide, Algal,Peptides, Algal,Product, Algal Gene,Protein, Algal,Protein, Algal Gene,Proteins, Algal