491 research outputs found
Studies on the synthesis of mitochondrial proteins in the cytoplasm and on their transport into the mitochondria
No full textProtein translocation across mitochondrial membranes
No full textProtein translocation across biological membranes is of fundamental importance for the biogenesis of organelles and in protein secretion. We will give an overview of the recent achievements in the understanding of protein translocation across mitochondrial membranes(1-5). In particular we will focus on recently identified components of the mitochondrial import apparatus
Partial sequence of a chloroform-methanol soluble polypeptide from Neurospora mitochondrial membranes
No full textApocytochrome c
No full textThe cytochrome c import pathway differs markedly from the general route taken by the majority of other imported proteins, which is characterized by the import involvement of namely, surface receptors, the general insertion protein (GIP), contact sites and by the requirement of a membrane potential (Δψ). Unique features of both the cytochrome c precursor (apocytochrome c) and of the mechanism that transports it into mitochondria, have contributed to the evolution of a distinct import pathway that is not shared by any other mitochondrial protein analysed thus far. The cytochrome c pathway is particularly unique because i) apocytochrome c appears to have spontaneous membrane insertion-activity; ii) cytochrome c heme lyase seems to act as a specific binding site in lieu of a surface receptor and; iii) covalent heme addition and the associated refolding of the polypeptide appears to provide the free energy for the translocation of the cytochrome c polypeptide across the outer mitochondrial membrane
Studies on the synthesis of mitochondrial proteins in the cytoplasm and on their transport into the mitochondria
No full textCytosolic protein Vms1 links ribosome quality control to mitochondrial and celluler homeostasis. Izawa and Park et al.
No full textImages for immunoblot
Mitochondrial porin of Neurospora crassa
No full textcDNA encoding porin of Neurospora crassa, the major protein component of the outer mitochondrial membrane, was isolated and the nucleotide sequence was determined. The deduced protein sequence consists of 283 amino acids (29,979 daltons) and shows sequence homology of around 43% to yeast porin; however, no significant homology to bacterial porins was apparent. According to secondary structure predictions, mitochondrial porin consists mainly of membrane-spanning sided beta-sheets. Porin was efficiently synthesized in vitro from the cDNA; this allowed us to study in detail its import into mitochondria. Thereby, three characteristics of import were defined: (i) import depended on the presence of nucleoside triphosphates; (ii) involvement of a proteinaceous receptor-like component on the surface of the mitochondria was demonstrated; (iii) insertion into the outer membrane was resolved into at least two distinct steps: specific binding to high-affinity sites and subsequent assembly to the mature form
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