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971.
K Kubota H Yamaki T Nishimura 《Biochemical and biophysical research communications》1973,52(2):489-495
In cell-free protein synthesis by the murine plasmacytoma X5563, which had become a nonproducing mutant, mixed systems with free polyribosomes and mirosomes incorporated 14C-amino-acid into protein 3–8 times greater than the sum of the incorporations in the individual system irrespective of S-100 concentrations. This enhancement was inhibited by lecithinase A and was markedly reduced at high KCl concentrations. Smooth endoplasmic membranes had more stimulatory activity than rough endoplasmic membranes. The results indicate that the membrane of the endoplasmic reticulum and free polyribosomes interact in the cell-free protein-synthesizing system, resulting in the enhancement of protein synthesis. 相似文献
972.
Washing spinach chloroplasts with high-concentration Tris-saltbuffers induced various types of anion-dependent changes inthe electron flow and photophosphorylation in chloroplasts. Tris-HCl buffer caused enhancement of NADP photoreduction andinhibition of phosphorylation. Tris-HNO3 buffer, on the otherhand, caused inhibition of both electron flow and phosphorylationand decreased trypsin-activated Ca2+-dependent ATPase activity.Tris-H2SO4 and Tris-H3PO4 buffers, however, had no effect onthe rates of electron flow and photophosphorylation. Determination of the presence of the coupling factor (as measuredby ATPase activity) revealed a normal enzyme activity levelin chloroplasts washed with Tris-HCl or Tris-H2SO4 buffer. Removalof the coupling factor by EDTA from chloroplasts washed withTris salts inhibited phosphorylation severely. Phosphorylationactivity could be partially restored by reconstitution withthe coupling factor in die presence of Mg2+. In addition to their different effects on electron flow, Tris-HCland Tris-HNO3 induced a marked decrease in phosphorylative activityitself. The much decreased rate of phosphorylation can be explainedby the release of the coupling factor and by damage to the high-energystate generating mechanism by Tris-HNO3-washing and by modificationof the coupling factor in the case of Tris-HCl-washing.
1Present address: Biology Department, College of Science andEngineering, Ryukyu University, Naha, Okinawa. Japan. (Received June 27, 1972; ) 相似文献
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Shigeki Suzuki Hiroaki Hoshino Kazuma Yoshida Jun Nakanishi Shizu Tsuchiya-Hirata Seiji Kobuke Naoto Haruyama Fusanori Nishimura Hideki Shiba 《Biochemical and biophysical research communications》2018,495(3):2303-2309
Chromatin-enriched noncoding RNAs (ncRNAs) have emerged as key molecules in epigenetic processes by interacting with chromatin-associated proteins. Recently, protein-coding mRNA genes have been reported to be chromatin-tethered, similar with ncRNA. However, very little is known about whether chromatin-enriched mRNA is involved in the chromatin modification process. Here, we comprehensively examined chromatin-enriched RNA in squamous cell carcinoma (SQCC) cells by RNA subcellular localization analysis, which was a combination of RNA fractionation and RNA-seq. We identified 11 mRNAs as highly chromatin-enriched RNAs. Among these, we focused on the dentin matrix protein-1 (DMP-1) gene because its expression in SQCC cells has not been reported. Furthermore, we clarified that DMP-1 mRNA was retained in chromatin in its unspliced form in SQCC in vitro and in vivo. As the inhibition of the unspliced DMP-1 mRNA (unspDMP-1) expression resulted in decreased cellular proliferation in SQCC cells, we performed ChIP-qPCR to identify cell cycle-related genes whose expression was epigenetically modified by unspDMP-1, and found that the CDKN1B promoter became active in SQCC cells by inhibiting unspDMP-1 expression. This result was further validated by the increased CDKN1B gene expression in the cells treated with siRNA for unspDMP-1 and by restoration of the decreased cellular proliferation rate by simultaneously inhibiting CDKN1B expression in SQCC cells. Further, to examine whether unspDMP-1 was able to associate with the CDKN1B promoter region, SQCC cells stably expressing PP7-mCherry fusion protein were transiently transfected with the unspDMP-1 fused to 24 repeats of the PP7 RNA stem loop (unspDMP-1-24xPP7) and we found that unspDMP-1-24xPP7 was efficiently precipitated with the antibody against mCherry and was significantly enriched in the CDKN1B promoter region. Thus, unspDMP-1 is a novel chromatin-enriched RNA that epigenetically regulates cellular proliferation of SQCC. 相似文献
980.
Taichi Ikedo Manabu Minami Hiroharu Kataoka Kosuke Hayashi Manabu Nagata Risako Fujikawa Fumiyoshi Yamazaki Mitsutoshi Setou Masayuki Yokode Susumu Miyamoto 《Biochemical and biophysical research communications》2018,495(1):332-338