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H Fukami

Publications and source records attributed to H Fukami.

65 records · Page 4Linked to original sources
PubMed1976

In vitro translation of globin: effect of proteins purified by affinity chromatography on polyadenylate-Sepharose.

By means of affinity chromatography on poly(adenylic acid) (poly(A))-fixed Sepharose, protein fractions having strong affinity to poly(A) were prepared from postribosomal supernatants of rabbit reticulocyte and rat liver. These fractions contained several proteins similar by electrophoretic analysis to rabbit globin messenger ribonucleoprotein. Protein fractions from both sources were shown to form ribonucleoprotein complexes with rabbit globin mRNA, and these complexes sedimented at the same rate as native globin messenger ribonucleoprotein. Binding of the proteins to RNA was not highly specific, since not only poly(A) but also other polynucleotides as poly(C) or poly(U) were bound to these proteins. Ribosomal RNAs, tRNA, or DNAs did not bind the proteins. In order to ascertain the function of the poly(A)-Sepharose purified proteins, their effects on translation of globin mRNA was studied in vitro. Addition of rabbit reticulocyte protein to globin mRNA resulted in no more than a slight stimulation of both alpha- and beta-chain synthesis. Poly(A)-Sepharose purified protein from rat liver, however, caused a marked preferential reduction of alpha-chain synthesis. These results showed that at least some proteins in the poly(A)-Sepharose purified proteins affect the translation of globin. This inference suggested a possibility that protein moiety in globin mRNP might be involved in control of globin synthesis.

Animals↗
PubMed1971

Control of translation by the conformation of messenger RNA.

This study concerns the question of whether protein biosynthesis is controlled by the conformation of messenger RNA. When R17 bacteriophage RNA was first incubated in the presence of Mg(++) before being used as messenger in a cell-free system from Escherichia coli, significant changes in the incorporation of phenylalanine and histidine into protein were seen. The amounts of proteins synthesized were also altered. The changes were not due to degradation of R17 RNA nor to denaturation of a contaminating repressor; they could be reversed by appropriate treatment of the RNA. There forms of R17 RNA are therefore postulated for the control mechanism and characterized by their translational behavior. The significance of these forms with respect to their conformation is discussed.

Carbon Isotopes↗
PubMedDate not supplied

Comparative genetics of host response to N-methyl 1-N'-nitro-N-nitrosoguanidine. I. A lack of tumor production in the glandular stomach of Swiss mouse.

The present study investigated the effects of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) drink and 3 maintenance diets on both the survival and the glandular stomach morphology in a total of 480 Swiss/ICR mice. The MNNG conditioning was practised in one half of the mice for the first 8 months. The maintenance of mice on the standard (MF) diet, the rice-rich (R) diet or the rice- and salt-rich (RS) diet was continued for 12 months. The results obtained are as follows: 1) Many mice in the MNNG-conditioned groups experienced fatal bleeding into the small intestine before the termination of the feeding experiment. There was no sign of tumor formation in their digestive canals. The bleeding deaths took place more often in the MF- and RS- diet groups than in the R-diet groups, and started to appear earlier in males than in females within the MF-diet groups. 2) The tendency to gastric atophy, as assessed in terms of the wet weight of mouse glandular stomach as well as the quantitation of histological changes of the same organ in the one-year survivors, progressed in the order of the MF-diet groups, the R-diet groups and the RS-diet groups. 3) The effect of MNNG drink on the mouse glandular stomach morphology was bidirectional: it increased the incidence of advanced atrophy (and/or decreased the incidence of advanced hyperplasia) in the MF- and R-diet groups, and rather reduced the atrophy-oriented effect of the diet on stomach morphology in the RS-diet groups. 4) The above-mentioned effects of 3 maintenance diets and MNNG drink were more prominent in males than in females. 5) No neoplastic change was detected in the glandular stomachs of the one-year survivors with and without MNNG conditioning. 6) Evidence was presented to indicate that MNNG behaved as a quasi-antiandrogen in inducing the morphological changes of mouse glandular stomach.

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