In transcriptional regulation, RNA polymerase II (pol II) interacts and forms complexes with a number of protein factors. To isolate and identify the pol II-associated proteins, we constructed a Schizosaccharomyces pombe strain carrying a FLAG tag sequence fused to the rpb3 gene encoding the pol II subunit Rpb3. By immunoaffinity purification with anti-FLAG antibody-resin, a pol II complex containing the Rpb1 subunit with a nonphosphorylated carboxyl-terminal domain (CTD) was isolated. In addition to the pol II subunits, the complex was found to contain three subunits of a transcription factor TFIIF (TFIIF␣, TFIIF␤, and Tfg3) and TFIIF-interacting CTD-phosphatase Fcp1. The same type of pol II complex could also be purified from an Fcp1-tagged strain. The isolated Fcp1 showed CTD-phosphatase activity in vitro. The fcp1 gene is essential for cell viability. Fcp1 and pol II interacted directly in vitro. Furthermore, by chemical cross-linking, glutathione S-transferase pulldown, and affinity chromatography, the Fcp1-interacting subunit of pol II was identified as Rpb4, which plays regulatory roles in transcription. We also constructed an S. pombe thiamine-dependent rpb4 shut-off system. On repression of rpb4 expression, the cell produced more of the nonphosphorylated form of Rpb1, but the pol II complex isolated with the anti-FLAG antibody contained less Fcp1 and more of the phosphorylated form of Rpb1 with a concomitant reduction in Rpb4. This result indicates the importance of Fcp1-Rpb4 interaction for formation of the Fcp1/TFIIF/pol II complex in vivo.RNA polymerase II (pol II), which is involved in the synthesis of all mRNAs, is a highly structured complex consisting of as many as 12 subunits, Rpb1 to Rpb12 (30,37,60,67,75), but for accurate transcription, pol II is controlled by a number of factors through protein-protein interactions (56). In preinitiation complex (PIC) formation, a general transcription factor (GTF), TFIIF, associates with pol II to recruit it to the complex on a promoter, which is formed of GTFs, including TFIIA, TFIIB, and TFIID (19). TFIIB (22,39,68) and one of the TATA binding protein (TBP)-associating factor (TAF) subunits of TFIID (7) interacts with pol II, and the TBP subunit of TFIID also binds to the nonphosphorylated carboxyterminal domain (CTD) of Rpb1 (69). TFIIE assembles into the complex through direct interaction with pol II (39, 46) and then promotes association of TFIIH, which phosphorylates the CTD (17, 43, 51). The kinase subunit of TFIIH binds to pol II (18).The alternative pathway of PIC formation is the prior assembly of pol II and factors to form pol II holoenzyme (38,50). This large complex consists of pol II, a subset of GTFs, and a mediator complex, and it is recruited to a promoter through the interaction of mediators with DNA-binding activators. In the holoenzyme, the mediator complex, which is composed of SRBs (for suppressor of RNA pol B), mediators, and other subunits, is attached to the CTD (49) and possibly other parts of pol II (3). Srb10 in the mediator comp...

Phosphosilicate glass (PSG) films were deposited onto silicon substrates by the oxidation of SiH4 and PH3  at 350°. Densities, phosphorus oxide concentrations, and infrared absorption spectra were measured for the evaluation of the film structure. It was found that nearly all the phosphorus oxide in a PSG film containing more than about 8 mole per cent P2O5 was dissolved into water by exposing to saturated water vapor at 120°C. By heating at elevated temperatures, the phosphorus oxide concentration value at which phosphorus oxide began to dissolve shifted toward the higher concentration region. Water absorption in the PSG film also can be lessened considerably by heat‐treatment.

The aim of this study was to calculate the expected incidences of chromosome abnormalities found at amniocentesis in Japanese women aged 35 and older. From four clinics in Japan, we gathered genetic amniocentesis data on 5484 pregnant women at risk only due to their advanced age, 35 years and older. We analyzed the data using the logistic regression model. Of the 5484 fetuses, 117 (2.1%) were diagnosed with a chromosome abnormality. The abnormal karyotypes included 42 cases of trisomy 21; 13 of trisomy 18; 7 of trisomy 13; 10 of 47,XXY; 4 of 47,XXX; 1 of 47,XYY; 27 with various structural aberrations; and 13 with various types of mosaicism. The incidences of trisomy 21, lethal autosomal aneuploidies (trisomy 18 and trisomy 13), and sex-chromosome abnormalities (XXY, XXX, XYY) increased with maternal age. Parameters of the regression equations with their standard errors were calculated and the expected incidences of chromosome abnormalities at each maternal age were derived. The expected incidences of chromosome abnormalities obtained in this study are the first data published for Japan and will be useful for the counseling of pregnant women. The incidence of trisomy 21 is not different from the rates published previously for Western countries. The incidences of chromosome abnormalities are not affected by race or by geographic factors.

Reducing the environmental burden and assessing the safety of plastics are huge global challenges. However, standard test data on the ready biodegradability of plastics are limited. We evaluated the ready biodegradability of 8 biodegradable plastics using Organisation for Economic Co‐operation and Development (OECD) test guideline 301F with nonspecific bacteria and examined the effects of prolonging the test duration to a maximum of 90 d. Cellulose used as a potential reference material for plastics was not comparable to the reference material of OECD test guideline 301, but it may be improved by using a test concentration lower than the typical test concentration (100 mg/L). Of the 8 plastics examined, polyamide 4, poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate), polycaprolactone, and poly(butylene succinate adipate; PBSA) were biodegraded by >60% by day 28 and considered to show ready biodegradability. Poly(3‐hydroxybutyrate; PHB), poly(3‐hydroxybutyric acid‐co‐3‐hydroxyvaleric acid; PHBV), and poly(butylene succinate; PBS) were biodegraded but did not fulfill the ready biodegradability criteria. Because the typical test concentration is considered to have negative effects on biodegradation and calculation of biodegradation percentage, using a lower concentration may result in PHB, PHBV, and PBS fulfilling the ready biodegradability criteria. Poly(d,l‐lactide; PLA) was not biodegraded. The biodegradation of PBS and PBSA was noted to vary depending on the used inoculum and/or particle size. For the 7 plastics except PLA, the percentage biodegradation on day 60 was larger than that on day 28, indicating that a longer test period could be useful for evaluating the environmental persistence of plastics. In tests in which the plastics were not biodegraded by day 60, no marked biodegradation was observed by day 90. Environ Toxicol Chem 2021;40:2443–2449. © 2021 SETAC