A restricted cytoplasmic region of IL-2 receptor beta chain is essential for growth signal transduction but not for ligand binding and internalization

The functional, high affinity form of interleukin-2 receptor (IL-2R) is composed of two receptor components, the IL-2R alpha (p55) and IL-2R beta (p70-75) chains. Unlike the IL-2R alpha chain, the IL-2R beta chain contains a large cytoplasmic domain that shows no obvious tyrosine kinase motif. In the present study, we report the establishment of a system in which the cDNA-directed human IL-2R beta allows growth signal transduction in a mouse pro-B cell line. This system enabled us to identify a unique region within the cytoplasmic domain of the human IL-2R beta chain essential for ligand-mediated signal transduction. We also demonstrate that certain cytoplasmic deletion mutants in the IL-2R beta chain, although deficient in signal transduction, can still form high affinity IL-2R in conjunction with endogenous mouse IL-2R alpha chain; the mutants are still able to internalize the ligand as well.     

Experiments inducing prospective polar body nuclei to participate in embryogenesis of the sawfly Athalia rosae (Hymenoptera)

Summary Mature eggs dissected from ovaries of unmated females of Athalia rosae (Hymenoptera: Tenthredinidae), if placed on a filter-paper soaked with distilled water, are activated and develop to haploid males. Occasionally, however, diploid females develop from these artificially activated eggs. Treatment of mature unfertilized eggs dissected from diploid females with ice-cold temperatures immediately before activation and with a high temperature (36° C) upon and immediately after activation resulted in the production of diploid males, diploid females, triploid females and gynandromorphs at high frequency. The same treatment of mature unfertilized eggs dissected from triploid females resulted in the production of only triploid survivors. These results, together with the results on the segregation of a marker mutation, yellow fatbody (yfb), appear to indicate that meiotic divisions were complete in the treated eggs, and that all four nuclei became potentially capable of participating in development with or without automictic fusion.Studies on the sawfly, Athalia rosae (Insecta, Hymenoptera, Tenthredinidae), part V     

Continuous acetic acid production by the bioreactor system loading a new ceramic carrier for microbial attachment

Summary We have developed a bioreactor system for aerobic fermentation, using a new ceramic carrier APHROCELL which has a suitable shape for liquid and gas passage. In acetic acid fermentation byAcetobacter cells from ethanol, as a typical example of aerobic fermentation, a productivity of 17.25 g/l h was attained at continuous production of 23 g-acetic acid/l; at an acetic acid concentration around 53 g/l, the productivity was 6.4 g/l h. Thus a marketable vinegar can be obtained continuously by this bioreactor system. Because of the simplicity of the APHROCELL reactor, scale up should be relatively easy.     

The primary structures of ribosomal proteins L16, L23 and L33 from the archaebacterium Halobacterium marismortui

The complete amino acid sequences of ribosomal proteins L16, L23 and L33 from the archaebacterium Halobacterium marismortui were determined. The sequences were established by manual sequencing of peptides produced with several proteases as well as by cleavage with dilute HCl. Proteins L16, L23 and L33 consist of 119, 154 and 69 amino acid residues, and their molecular masses are 13538, 16812 and 7620 Da, respectively. The comparison of their sequences with those of ribosomal proteins from other organisms revealed that L23 and L33 are related to eubacterial ribosomal proteins from Escherichia coli and Bacillus stearothermophilus, while protein L16 was found to be homologous to a eukaryotic ribosomal protein from yeast. These results provide information about the special phylogenetic position of archaebacteria.     

Evidence for involvement of tryptophan residue in the low-affinity saccharide binding site of ricin D

The nature of the saccharide-binding site of ricin D, which is a galactose- and N-acetylgalactosamine-specific lectin, was studied by chemical modification and spectroscopy. With excitation at 290 nm, ricin D displayed a fluorescence spectrum with a maximum at 335 nm. Upon binding of the specific saccharides, the spectrum shifted to shorter wavelength by 3 nm. However, binding of galactosamine and N-acetylgalactosamine failed to induce such a change in the fluorescence spectrum. The interaction of ricin D with its specific saccharides was analyzed in terms of the variation of the intensity at 320 nm as a function of saccharide concentration. The results indicate that the change in the fluorescence spectrum induced by saccharide binding is attributable to the binding of saccharide to the low-affinity (LA-) binding site of ricin D. The cytoagglutinating activity of ricin D decreased to 2% upon modification of two tryptophan residues/mol with N-bromosuccinimide at pH 4.0, but in the presence of galactose or lactose one tryptophan residue/mol remained unmodified, and a fairly high cytoagglutinating activity was retained. Galactosamine and N-acetylgalactosamine did not show such a protective effect. Spectroscopic analyses indicate that the decrease in the cytoagglutinating activity of ricin D upon tryptophan modification is principally due to the loss of the saccharide binding activity of the LA-binding site. The results suggest that one tryptophan residue is essential for saccharide binding at the LA-binding site, which can bind galactose and lactose but lacks the ability to bind N-acetylgalactosamine and galactosamine.     

Purification and characterization of poly(ADP-ribose) glycohydrolase. Different modes of action on large and small poly(ADP-ribose)

Poly(ADP-ribose) glycohydrolase was purified approximately 74,000-fold to apparent homogeneity from calf thymus with a yield of 3.2%. The enzyme was a monomeric protein of Mr = 59,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The action of glycohydrolase on poly(ADP-ribose) was exoglycosidic in the direction of adenosine terminus----ribose terminus; radioactive ADP-ribose monomers were immediately produced from evenly labeled poly(ADP-ribose), but not from the polymer labeled selectively at the ribose terminus. The enzymatic degradation of large poly(ADP-ribose) (greater than 20 ADP-ribose residues) proceeded in a biphasic as well as bimodal manner. In the early and rapid phase, the enzyme degraded part of large polymers successively, leaving the remainder completely intact, and accumulated ADP-ribose monomers and small polymers of the size less than half of original polymers, indicating that the enzyme action was processive up to a certain extent. In the late and 20-fold slower phase, by contrast, the enzyme degraded the accumulated small polymers gradually and evenly, i.e. in a nonprocessive manner. The Km for large polymers was approximately 100-fold lower than that for small polymers. Similar rates and processivities were observed with large and small polymers bound to various proteins. These results suggested that the glycohydrolase may regulate differentially the levels of large and small poly(ADP-ribose) in the cell.     

Harderianization is another sexual dimorphism of rat exorbital lacrimal gland

The exorbital lacrimal glands (ELG) of rats were examined for both sexes to determine what degree of harderianization occurred as a function of age and after castration, and to investigate its time course and origin in ELG. Light microscopically, very small Harderian foci were seen in the ELG of both sexes at 3 weeks of age. As the male rats became older, the relative volume of the Harderian gland (HG) cells in the ELG increased. At age 6 months, the value was 1.25 +/- 0.31% in males and 0.13 +/- 0.05% in females (p less than 0.05). After castration, a significant decrease (0.21 +/- 0.01%, p less than 0.05) was observed in that of male ELG. In contrast, in female ELG, HG cells were inconspicuous and the relative volume of those did not vary during this experimental period or after castration. It appeared that the HG cells had developed from undifferentiated basal cells of the acini and the intercalated ducts in the ELG at age 2-6 months. Then, at age 22 months, they also probably developed from those of the excretory ducts of the ELG.     

Intravesical treatment of bladder cancer with recombinant human interferon-β

Summary In order to examine its clinical efficacy, recombinant human interferon- (rIFN-) was instilled intravesically into 51 patients with superficial bladder cancer. Ten patients, who received intermittent intravesical instillation at a dose of (3–36) × 10⁶ U rIFN- on days 1–3 every week, showed no response. Thirty-two patients received intravesical instillation at a dose of (3–36) × 10⁶ U every day for 10–20 days. Eight patients showed partial response, indicating an efficacy rate of 25%. Nine patients received divided doses of 18 × 10⁶ U twice a day every day for 10–20 days. Six patients showed partial response, indicating an efficacy rate of 67%. This value was significantly higher than that obtained by administering divided doses. The response to intravesical instillation therapy with rIFN- varies with treatment protocol. Frequent and longer exposure to rIFN- may induce better regression of superficial bladder cancer. Six incidences of side-effects were found in five cases (9.8%): pollakiuria in one, pain on micturition in two, fever in two, and eruption in one case. All of these side-effects were slight and reversible after drug withdrawal. Laboratory tests showed only a few changes with low severity. Thus, rIFN- is potentially a new drug for instillation therapy of superficial bladder cancer, in view of the absence of adverse effects.     

A microassay for proteases using succinylcasein as a substrate.

A photometric assay for proteases has been developed. A chemically modified casein whose amino groups were succinylated was used as a substrate. After incubation with trypsin, chymotrypsin, thermolysin, and subtilisin, the extent of hydrolysis of the substrate was determined with trinitrobenzene sulfonate (TNBS). The whole procedure of the assay was performed in the microtiter plate wells and the increase in the absorbance resulting from the reaction between TNBS and newly formed amino groups in the substrate was able to be determined with a high sensitivity by a microtiter plate reader, enabling the simultaneous measurement of a number of samples. Application of this method to the measurement of proteolytic activity contained in the protein extract of Tapes philippinarum is demonstrated.