3,708 research outputs found
Mitochondrial Translation Products before and after Integration into the Mitochondrial Membrane in Neurospora crassa
# 1.
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 peptidyl transfer RNA products at 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. In contrast, translation products associated with cytoplasmic monomeric and polymeric ribosomes all show quite disperse molecular weights.
# 4.
Using gel-chromatographic analysis no difference in the elution characteristics between translation products associated with mitochondrial monomeric and polymeric ribosomes was found. In both cases apparent molecular weights of about 11000 were obtained.
# 5.
A kinetic study of the appearance of mitochondrial translation products in the mitochondrial membrane was carried out. A conversion process of products with lower apparent molecular weights to those with higher apparent molecular weights is observed. This suggests that mitochondrial ribosomes form polypeptides which are modified during or after integration into the membrane.
# 6.
The hypothesis is discussed that mitochondria possess their own system of transcription and translation, because the hydrophobic nature of the translation products makes it necessary that they are formed inside the inner mitochondrial membrane, into which they are integrated
Nascent polypeptide chains on mitochondrial ribosomes and their integration into the inner membrane
Über die Funktion der mitochondrialen Ribosomen bei der Bildung der mitochondrialen Innenmembran
Nascent polypeptide chains on mitochondrial ribosomes and their integration into the inner membrane
Über die gegenseitige Abhängigkeit von mitochondrialer und cytoplasmatischer Translation bei der Bildung der Innenmembran von Mitochondrien in Neurospora crassa
Partial sequence of a chloroform-methanol soluble polypeptide from Neurospora mitochondrial membranes
Herding Vulnerable Cats: A Statistical Approach to Disentangle Joint Responsibility for Web Security in Shared Hosting
Hosting providers play a key role in fighting web compromise, but their
ability to prevent abuse is constrained by the security practices of their own
customers. {\em Shared} hosting, offers a unique perspective since customers
operate under restricted privileges and providers retain more control over
configurations. We present the first empirical analysis of the distribution of
web security features and software patching practices in shared hosting
providers, the influence of providers on these security practices, and their
impact on web compromise rates. We construct provider-level features on the
global market for shared hosting -- containing 1,259 providers -- by gathering
indicators from 442,684 domains. Exploratory factor analysis of 15 indicators
identifies four main latent factors that capture security efforts: content
security, webmaster security, web infrastructure security and web application
security. We confirm, via a fixed-effect regression model, that providers exert
significant influence over the latter two factors, which are both related to
the software stack in their hosting environment. Finally, by means of GLM
regression analysis of these factors on phishing and malware abuse, we show
that the four security and software patching factors explain between 10\% and
19\% of the variance in abuse at providers, after controlling for size. For
web-application security for instance, we found that when a provider moves from
the bottom 10\% to the best-performing 10\%, it would experience 4 times fewer
phishing incidents. We show that providers have influence over patch
levels--even higher in the stack, where CMSes can run as client-side
software--and that this influence is tied to a substantial reduction in abuse
levels
Action of intracellular proteinases on mitochondrial translation products of Neurospora crassa and Schizosaccharomyces pombe
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