Cloning and analysis of the Neurospora crassa gene for cytochrome c heme lyase

Drygas, Mariola E.; Lambowitz, Alan M.; Nargang, Frank E.

doi:10.1016/s0021-9258(19)84657-4

Cited by 92 publications

(6 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[117][118][119][120][121] Heme c is structurally similar to heme b except that thioether bonds to cysteine residues replace one or both of the vinyl groups and covalently link the heme macrocycle directly to the protein scaffold. 122 The covalent attachment of heme to the protein is effected by the enzyme heme lyase, 123 but in vitro chemical synthesis has also been used to form the thioether bonds in b-type cytochrome and c-type cytochrome scaffolds. [124][125][126][127] Cytochromes c typically contain a CXXCH sequence motif from which the two cysteines link to the porphyrin macrocycle and the histidine binds to the encapsulated iron.…”

Section: Overview Of Natural Heme Proteinsmentioning

confidence: 99%

Heme Protein Assemblies

2004

View full text Add to dashboard Cite

Section: Overview Of Natural Heme Proteinsmentioning

confidence: 99%

Heme Protein Assemblies

2004

View full text Add to dashboard Cite

“…CCHL, a peripheral protein of the inner membrane facing the intermembrane space, is imported into mitochondria without the need of a membrane potential across the inner membrane (Lill et al, 1992). It does not contain a cleavable, NH2-terminal signal sequence (Drygas et al, 1989). After incubation of in vitro translated CCHL with outer membrane vesicles, a fraction of the protein became protease-protected (Fig.…”

Section: The Protein Translocation Activity Of Purified Outer Membrane Vesiclesmentioning

confidence: 99%

Translocation and insertion of precursor proteins into isolated outer membranes of mitochondria.

Mayer

Lill

Neupert

1993

The Journal of Cell Biology

123

102

View full text Add to dashboard Cite

Abstract. Nuclear-encoded proteins destined for mitochondria must cross the outer or both outer and inner membranes to reach their final sub-mitochondrial locations. While the inner membrane can translocate preproteins by itself, it is not known whether the outer membrane also contains an endogenous protein translocation activity which can function independently of the inner membrane. To selectively study the protein transport into and across the outer membrane of Neurospora crassa mitochondria, outer membrane vesicles were isolated which were sealed, in a right-side-out orientation, and virtually free of inner membranes. The vesicles were functional in the insertion and assembly of various outer membrane proteins such as porin, MOM19, and MOM22. Like with intact mitochondria, import into isolated outer membranes was dependent on protease-sensitive surface receptors and led to correct folding and membrane integration. The vesicles were also capable of importing a peripheral component of the inner membrane, cytochrome c heme lyase (CCHL), in a receptor-dependent fashion. Thus, the protein translocation machinery of the outer mitochondrial membrane can function as an independent entity which recognizes, inserts, and translocates mitochondrial preproteins of the outer membrane and the intermembrane space. In contrast, proteins which have to be translocated into or across the inner membrane were only specifically bound to the vesicles, but not imported. This suggests that transport of such proteins involves the participation of components of the intermembrane space and/or the inner membrane, and that in these cases the outer membrane translocation machinery has to act in concert with that of the inner membrane.

show abstract

“…Furthermore, cytochrome c is highly conserved during evolution. Like most mitochondrial proteins, cytochrome c is encoded by a nuclear gene and synthesized as a cytoplasmic precursor molecule, apocytochrome c , which becomes selectively imported into the mitochondrial intermembrane space where a heme group is covalently attached via thioether linkages to cysteine residues, near the amino‐terminus of apocytochrome c by the heme lyase (Dumont et al ., 1987; Nicholson et al ., 1987; Drygas et al ., 1989; Stuart and Neupert, 1990).…”

Section: Introductionmentioning

confidence: 99%

Mitochondrial cytochrome c release in apoptosis occurs upstream of DEVD-specific caspase activation and independently of mitochondrial transmembrane depolarization

1998

View full text Add to dashboard Cite

Mitochondrial cytochrome c, which functions as an electron carrier in the respiratory chain, translocates to the cytosol in cells undergoing apoptosis, where it participates in the activation of DEVD-specific caspases. The apoptosis inhibitors Bcl-2 or Bcl-x L prevent the efflux of cytochrome c from mitochondria. The mechanism responsible for the release of cytochrome c from mitochondria during apoptosis is unknown. Here, we report that cytochrome c release from mitochondria is an early event in the apoptotic process induced by UVB irradiation or staurosporine treatment in CEM or HeLa cells, preceding or at the time of DEVD-specific caspase activation and substrate cleavage. A reduction in mitochondrial transmembrane potential (Δψ m ) occurred considerably later than cytochrome c translocation and caspase activation, and was not necessary for DNA fragmentation. Although zVAD-fmk substantially blocked caspase activity, a reduction in Δψ m and cell death, it failed to prevent the passage of cytochrome c from mitochondria to the cytosol. Thus the translocation of cytochrome c from mitochondria to cytosol does not require a mitochondrial transmembrane depolarization.

show abstract

Cloning and analysis of the Neurospora crassa gene for cytochrome c heme lyase

Cited by 92 publications

References 36 publications

Heme Protein Assemblies

Heme Protein Assemblies

Translocation and insertion of precursor proteins into isolated outer membranes of mitochondria.

Mitochondrial cytochrome c release in apoptosis occurs upstream of DEVD-specific caspase activation and independently of mitochondrial transmembrane depolarization

Contact Info

Product

Resources

About