Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A ribonuclease activity that has characteristics expected for an enzyme that catalyzes the regulated destabilization of serum protein-coding mRNAs following estrogen administration was previously identified on Xenopus liver polysomes. This enzyme activity is estrogen inducible and selectively degrades mRNAs (e.g., albumin, gamma-fibrinogen) that are unstable following estrogen administration to male frogs. This paper reports on the relationship between this enzyme activity and the association of 40S and 60S ribosomal subunits. Ribonuclease activity (as defined by the generation of a specific cleavage fragment from albumin RNA) is found in polysome fractions that contain the majority of the liver mRNA. This activity sediments on sucrose gradients with the large polysome complexes observed in liver of vitellogenic animals. EDTA treatment generates 40S and 60S ribosome subunits and a significant amount of 80S ribosome monomers. Under these conditions, polysomal ribonuclease activity is found both free in solution and with the 80S material. Puromycin treatment generates predominantly 40S and 60S ribosomal subunits. Polysomal ribonuclease activity is found only in solution following puromycin treatment. These data indicate that the Xenopus liver polysomal nuclease requires the association of both ribosomal subunits for complex formation with polysomes. The polysomal nuclease behaves as a basic protein on Mono Q chromatography, with the fractionated material retaining the same differential activity toward albumin versus ferritin mRNA.
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PMID:The nuclease that selectively degrades albumin mRNA in vitro associates with Xenopus liver polysomes through the 80S ribosome complex. 837 69

In the aging human brain, the concentrations of iron and its major storage protein, ferritin, rise but the distribution of metal and protein remains non-uniform. More ferritin could be isolated from the brains of humans who died of Alzheimer's disease (AD) than from age- and sex-matched controls. Also, brain ferritin of rats chronically exposed to aluminum chloride in their drinking water contained more aluminum and iron. Based on these earlier observations, a more detailed study of human brain ferritin was initiated. The results showed that ferritin is a component of neuritic (senile) plaques in AD. Ferritin obtained from normal or AD brains is composed of 24 subunits (70% heavy (H) chain; 30% light (L) chain). With high performance liquid chromatography, the subunits resolved into a cluster of four H-chain peaks and one major L-chain peak. Western blot analysis confirmed the identity of H- and L-fractions. The techniques of molecular biology revealed the presence of an additional ferritin messenger ribonucleic acid (mRNA) species for the H subunit which was more abundant in the brain than in other human tissues. It contained the entire sequence of 919 nucleotides of H chain mRNA from liver but also an additional segment of 279 nucleotides in the 3'-untranslated region. The two mRNA seemed to arise by the use of an alternate polyadenylation site of the same primary transcript. Ribonuclease protection assays revealed that the concentrations of the longer mRNA in the normal hippocampus and the hippocampus of patients with AD brains were similar.
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PMID:A novel ferritin heavy chain messenger ribonucleic acid in the human brain. 884 45

The attachment to the surface of the ameba (Chaos chaos L. (Pelomyxa carolinensis, Wilson)) of two proteins, ribonuclease and ferritin, and two colloidal suspensions, thorium dioxide and gold, was studied in the electron microscope. The initial step in the pinocytosis of ferritin and thorium dioxide particles by amebas is shown to be the attachment of these substances to the "hairlike" extensions of the plasmalemma. Ribonuclease caused alterations in the structure of the plasmalemma, but on account of its relative lack of density, it could not be definitely localized. Colloidal gold did not appear to be active with respect to pinocytosis in amebas. Since molecules in solution and particles in suspension are taken up by the same mechanism, the first step of which is their attachment to the cell surface, it is suggested that a single mechanism underlies phagocytosis, pinocytosis, ropheocytosis, cytopempsis, and potocytosis.
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PMID:AN ELECTRON MICROSCOPIC STUDY OF PINOCYTOSIS IN AMEBA : I. The Surface Attachment Phase. 1986 75