Expression of the mitochondrial genome in HeLa cells

Ojala, Deanna; Attardi, Giuseppe

doi:10.1016/0022-2836(72)90282-3

Cited by 61 publications

(25 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Treatment of mitochondrial ribosomes with TI ribonuclease has the same result. A similar observation on the resistance against ribonuclease with mitochondrial ribosomes from HeLa cells has been made by Ojala and Attardi [21]. …”

Section: Effect Of Ribonuclease On Cytoplasmic and Mitochondria1 Ribosupporting

confidence: 79%

Mitochondrial Translation Products before and after Integration into the Mitochondrial Membrane in Neurospora crassa

Michel¹,

Neupert²

1973

European Journal of Biochemistry

View full text Add to dashboard Cite

I . Nascent translation products on mitochondrial ribosomes were selectively labeled in vivo in the presence of cycloheximide with radioactive leucine. They were isolated together with the ribosomes.2. The labeled polypeptides show a high tendency to aggregate and can only be kept in solution in the presence of detergents such as dodecylsulfate. Also, mitochondrial ribosomes carrying nascent peptide chains easily form aggregates.3. The polypeptides adhering to mitochondrial monomeric ribosomes differ from those adhering to polymeric ribosomes. Gel electrophoresis in the presence if dodecylsulfate shows for the peptidy1 transfer RNA products a t the monomer, an apparent molecular weight of 27000. After removing the transfer RNA, an apparent molecular weight of less than 10000 is registered. The peptides adhering to mitochondrial polymeric ribosomes display a broad range of apparent molecular weights. I n contrast, translation products associated with cytoplasmic monomeric and polymeric ribosomes all show quite disperse molecular weights.

show abstract

Section: Effect Of Ribonuclease On Cytoplasmic and Mitochondria1 Ribosupporting

confidence: 79%

Mitochondrial Translation Products before and after Integration into the Mitochondrial Membrane in Neurospora crassa

Michel¹,

Neupert²

1973

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

“…The mitochondrial fraction was separated by differential centrifugation and sucrose gradient fractionation, lysed with Triton X-100, and centrifuged at 20,000 X gay for 15 min. The supernatant was centrifuged on a sucrose gradient as described (2,21). RNA was extracted by the sodium dodecyl sulfatePronase-phenol method (22) from the material of the polysome region (74-180 S) of the sucrose gradient pattern.…”

Section: Methodsmentioning

confidence: 99%

Identification of Discrete Polyadenylate-containing RNA Components Transcribed from HeLa Cell Mitochondrial DNA

Ojala¹,

Attardi²

1974

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

Polyacrylamide gel electrophoresis and sedimentation analysis under denaturing conditions of poly(A)-containing RNA from the polysome region of the sedimentation pattern of a HeLa-cell mitochondrial lysate has revealed the occurrence of a discrete RNA component, which sediments in the native state with a sedimentation constant of about 7 S. From the sedimentation behavior under native and denaturing conditions and the poly(A) content, a molecular weight of about 9 X 104 has been estimated for this component. RNA-DNA hybridization experiments have indicated that this component is coded for by the light strand of mitochondrial DNA. Evidence for the occurrence of a poly(A)-containing RNA component sedimenting at about 9 S and coded for by the heavy strand has also been obtained.Poly(A) sequences of a size corresponding to 60-80 nucleotides occur in mitochondrial RNA from HeLa cells (1, 2); a poly(A)-synthesizing enzyme has been identified in rat-liver mitochondria (3,4). In HeLa cells, the majority of mitochondrial poly(A) is covalently linked to mitochondrial DNA (mit-DNA)-coded RNA (2). Inasmuch as poly(A) in eukaryotic cells appears to be associated only with cytoplasmic messenger RNA (mRNA) and its presumptive nuclear precursors (5-10), and with viral or viral-directed RNA with messenger function (5,(11)(12)(13)(14)(15), the above evidence strongly suggests that at least a portion of the mRNA translated by mitochondrial polysomes is coded for by mit-DNA.Previously (2), no clear-cut evidence of discrete components was observed in the sedimentation patterns of poly(A)-containing RNA from HeLa-cell mitochondria. The main source of difficulty was probably the tendency of poly(A)-containing molecules to aggregate and sediment with heavier molecules. Thus, RNA from the polysome region of the sedimentation pattern of a mitochondrial lysate, selected for poly(A) by two passages through poly(dT)-cellulose and analyzed in sucrose gradient in the native state, showed a fairly uniform distribution of material in the region from 6 S to about 16 S, with only a hint of a 7S component emerging over a background of heterogeneous RNA. After formaldehyde denaturation and sedimentation in the presence of formaldehyde, most of the poly-(A)-containing RNA sedimented more slowly than 12 S RNA, and a pronounced sharp peak sedimenting about 20% faster than denatured 5S RNA and 40% slower than denatured 12S RNA was observed. ,ug/ml of ethidium bromide (eih. brom.), and passed through poly(dT)-cellulose. The mitochondrial 12S RNA and cytoplasmic 5S RNA were treated as the experimental samples and run in parallel gels. RESULTSA Triton X-100 mitochondrial lysate from HeLa cells labeled for 2 hr with [8-8H]adenosine in the presence of 0.1 ug/ml of actinomycin D was run through a sucrose gradient, and RNA was extracted from the polysome region (74-180 S) of the gradient (21) and passed through a poly(dT)-cellulose column. It had been shown (1, 2) that poly(dT)-cellulose or poly(U) filters bind mitochondrial poly(A)-containing RNA, wh...

show abstract

“…Mitopolysomes have been reported in yeast (4,13), Euglena (14), and HeLa cells (15). We have used several lines of evidence to characterize the mitopolysomes: (a) sedimentation as large units in sucrose density gradients, (b) composition of rRNA, (c) direct yisu alization by electron microscopy as ribosomes connected by a strand of RNA, (d) sensitivity of ribosome association to ribonuclease, (e) function in protein synthesis.…”

Section: Discussionmentioning

confidence: 99%

Evidence of Involvement of Mitochondrial Polysomes and Messenger Rna in Synthesis of Organelle Proteins

Cooper¹,

Avers²

1974

The Biogenesis of Mitochondria

View full text Add to dashboard Cite

Expression of the mitochondrial genome in HeLa cells

Cited by 61 publications

References 34 publications

Mitochondrial Translation Products before and after Integration into the Mitochondrial Membrane in Neurospora crassa

Mitochondrial Translation Products before and after Integration into the Mitochondrial Membrane in Neurospora crassa

Identification of Discrete Polyadenylate-containing RNA Components Transcribed from HeLa Cell Mitochondrial DNA

Evidence of Involvement of Mitochondrial Polysomes and Messenger Rna in Synthesis of Organelle Proteins

Contact Info

Product

Resources

About