Structural organization of the beta-globin locus of B-haplotype sheep

Goats and some sheep synthesize a juvenile hemoglobin, Hb C (alpha 2 beta C2), at birth and produce this hemoglobin exclusively during severe anemia. Sheep that synthesize this juvenile hemoglobin are of the A haplotype. Other sheep, belonging to a separate group, the B haplotype, do not synthesize hemoglobin C and during anemia continue to produce their adult hemoglobin. To understand the basis for this difference we have determined the structural organization of the beta- globin locus of B-type sheep by constructing and isolating overlapping genomic clones. These clones have allowed us to establish the linkage map 5' epsilon I-epsilon II-psi beta I-beta B-epsilon III-epsilon IV- psi beta II-beta F3' in this haplotype. Thus, B sheep lack four genes, including the BC gene, and have only eight genes, compared with the 12 found in the goat globin locus. The goat beta-globin locus is as follows: 5' epsilon I-epsilon II-psi beta X-beta C-epsilon III-epsilon IV-psi beta Z-beta A-epsilon V-epsilon VI-psi beta Y-beta F3'. Southern blot analysis of A-type sheep reveals that these animals have a beta- globin locus similar to that of goat, i.e., 12 globin genes. Thus, the beta-globin locus of B-haplotype sheep resembles that of cows and may have retained the duplicated locus of the ancestor of cows and sheep. Alternatively, the B-sheep locus arrangement may be the result of a deletion of a four-gene set from the triplicated locus.      

Selective inhibition of prostaglandin biosynthesis by gold salts and phenylbutazone

Gold salts and phenylbutazone selectively inhibit the synthesis of PGF_2α and PGE₂ respectively. Lowered production of one prostaglandin species is accompanied by an increased production of the other. Selective inhibition by these drugs was observed in the presence of adrenaline, reduced glutathione and copper sulphate under conditions when most anti-inflammatory compounds inhibited PGE₂ and PGF_2α syntheses equally. It is postulated that selective inhibitors may have a different mode of action and beneficial effects may be related to the endogenous ratio of PGE to PGF required for normal function.     

Two silicone nontoxic fouling release coatings: Hydrosilation cured PDMS and CaCO3 filled,ethoxysiloxane cured RTV11

Two silicone coatings have been evaluated for barnacle adhesion. One coating is an unfilled hydrosilation cured polydimethylsiloxane (PDMS) network, while the other is a room temperature vulcanized (RTV), filled, ethoxysiloxane cured PDMS elastomer, RTV11^?. The adhesion strength of one species of barnacle, Balanus eburneus, to the hydrosilation coatings is in the range of 0.37–0.60 kg cm^‐2 while the corresponding range for RTV11 is 0.64–0.90 kg cm^‐2. The easier release of B. eburneus from the hydrosilation cured network compared to RTV11 is discussed in relationship to differences in bulk and surface properties. Preliminary results suggest bulk modulus may be the most important parameter in determining barnacle adhesion strength. In light or mechanical property analysis, a re‐evaluation of surface properties and chemical stability is presented.     

FFA cause hepatic insulin resistance by inhibiting insulin suppression of glycogenolysis

Free fatty acids (FFA) have been shown to inhibit insulin suppression of endogenous glucose production (EGP). To determine whether this is the result of stimulation by FFA of gluconeogenesis (GNG) or glycogenolysis (GL) or a combination of both, we have determined rates of GNG and GL (with (2)H(2)O) and EGP in 16 healthy nondiabetic volunteers (11 males, 5 females) during euglycemic-hyperinsulinemic (~450 pM) clamping performed either with or without simultaneous intravenous infusion of lipid plus heparin. During insulin infusion, FFA decreased from 571 to 30 micromol/l (P < 0.001), EGP from 15.7 to 2.0 micromol x kg(-1) x min(-1) (P < 0.01), GNG from 8.2 to 3.7 micromol x kg(-1). min(-1) (P < 0.05), and GL from 7.4 to -1.7 micromol x kg(-1). min(-1) (P < 0.02). During insulin plus lipid/heparin infusion, FFA increased from 499 to 1,247 micromol/l (P < 0.001). EGP decreased 64% less than during insulin alone (-5.1 +/- 0.7 vs. -13.7 +/- 3.4 micromol x kg(-1). min(-1)). The decrease in GNG was not significantly different from the decrease of GNG during insulin alone (-2.6 vs. -4.5 micromol x kg(-1). min(-1), not significant). In contrast, GL decreased 66% less than during insulin alone (-3.1 vs. -9.2 micromol x kg(-1). min(-1), P < 0.05). We conclude that insulin suppressed EGP by inhibiting GL more than GNG and that elevated plasma FFA levels attenuated the suppression of EGP by interfering with insulin suppression of GL.     

Infusion of glucose and lipids at physiological rates causes acute endoplasmic reticulum stress in rat liver

Endoplasmic reticulum (ER) stress has recently been implicated as a cause for obesity-related insulin resistance; however, what causes ER stress in obesity has remained uncertain. Here, we have tested the hypothesis that macronutrients can cause acute (ER) stress in rat liver. Examined were the effects of intravenously infused glucose and/or lipids on proximal ER stress sensor activation (PERK, eIF2-α, ATF4, Xbox protein 1 (XBP1s)), unfolded protein response (UPR) proteins (GRP78, calnexin, calreticulin, protein disulphide isomerase (PDI), stress kinases (JNK, p38 MAPK) and insulin signaling (insulin/receptor substrate (IRS) 1/2 associated phosphoinositol-3-kinase (PI3K)) in rat liver. Glucose and/or lipid infusions, ranging from 23.8 to 69.5 kJ/4 h (equivalent to between ~17% and ~50% of normal daily energy intake), activated the proximal ER stress sensor PERK and ATF6 increased the protein abundance of calnexin, calreticulin and PDI and increased two GRP78 isoforms. Glucose and glucose plus lipid infusions induced comparable degrees of ER stress, but only infusions containing lipid activated stress kinases (JNK and p38 MAPK) and inhibited insulin signaling (PI3K). In summary, physiologic amounts of both glucose and lipids acutely increased ER stress in livers 12-h fasted rats and dependent on the presence of fat, caused insulin resistance. We conclude that this type of acute ER stress is likely to occur during normal daily nutrient intake.     

Yasutomi Nishizuka's Discovery of Protein Kinase C

Studies on a Cyclic Nucleotide-independent Protein Kinase and Its Proenzyme in Mammalian Tissues. I. Purification and Characterization of an Active Enzyme from Bovine Cerebellum (Takai, Y., Kishimoto, A., Inoue, M., and Nishizuka, Y. (1977) J. Biol. Chem. 252, 7603–7609)Direct Activation of Calcium-activated, Phospholipid-dependent Protein Kinase by Tumor-promoting Phorbol Esters (Castagna, M., Takai, Y., Kaibuchi, K., Sano, K., Kikkawa, U., and Nishizuka, Y. (1982) J. Biol. Chem. 257, 7847–7851)Yasutomi Nishizuka (1932–2004) was born in Ashiya-city, Japan. He attended Kyoto University and obtained his M.D. in 1957 and his Ph.D. in 1962, working with Journal of Biological Chemistry (JBC) Classic author Osamu Hayaishi (1). He then spent a year as a postdoctoral fellow at Rockefeller University with Fritz Lipmann (also featured in a JBC Classic (2)) before returning to Kyoto University to resume work with Hayaishi. During this time, Nishizuka studied the biosynthesis of nicotinamide adenine dinucleotide (NAD), the involvement of GTP in ribosomal protein translation, and ADP-ribosylation by diphtheria toxin.Open in a separate windowYasutomi NishizukaIn 1969, Nishizuka accepted the position of full professor and head of the department of biochemistry at the Kobe University School of Medicine. There, Nishizuka became interested in the role of protein kinases in the regulation of cell functions. This led to his discovery of a novel protein kinase, which he published in the first paper reprinted here as the JBC Classic. As Nishizuka reported in that paper, he and his colleagues partially purified the kinase from bovine cerebellum. They found that the enzyme was capable of phosphorylating histone and protamine and that it probably was produced from its precursor protein by a limited proteolytic reaction. The detailed properties of the proenzyme and its conversion to active protein kinase were reported in a subsequent JBC paper (3). Nishizuka named this new enzyme “protein kinase C (PKC).”A paper published by Nishizuka two years later in the JBC (4) showed that PKC was activated without limited proteolysis by a membrane-associated factor in the presence of a low concentration of Ca²⁺. In 1980, he published another paper in the JBC (5) showing that the membrane-associated factor was diacylglycerol, which suggested that the lipid could be a novel second messenger generated by receptor-stimulated phosphoinositide hydrolysis. Nishizuka validated this idea by showing that treating platelets with a combination of a Ca²⁺ ionophore and membrane-permeant short chain diacylglycerol mimicked stimulation by the aggregating agent thrombin (6). This discovery was a major advance in the understanding of cell signaling.Nishizuka and his colleagues then discovered that PKC is the biological target of tumor-promoting phorbol esters. At that time, it was well known that croton oil augmented carcinogenesis when it was applied at weekly intervals to the skin of mice in conjunction with a very dilute solution of benz[a]pyrene in acetone. The oil contained phorbol ester, a powerful tumor promoter, and caused a wide variety of cellular responses that were similar to those seen with hormones. Nishizuka speculated that the phorbol ester was producing diacylglycerol to activate PKC. However, upon further investigation, he realized that the phorbol ester contained a diacylglycerol-like structure and thus might activate PKC directly. In a series of experiments, published in the second JBC Classic reprinted here, Nishizuka was able to show that the phorbol ester activated PKC directly. This discovery showed that PKC was important for cell proliferation and cancer. It also established the use of phorbol esters as crucial tools for the manipulation of PKC activation in intact cells, eventually allowing the elucidation of the wide range of cellular processes regulated by this enzyme.This research laid the foundation for an enormous number of studies on the complex PKC family, many of them from Nishizuka''s group.In 1975, Nishizuka became president of the University of Kobe, a position that he held until 2001. He received numerous awards and honors for his research, including the Gairdner Foundation International Award (1988), the Alfred P. Sloan Jr. Prize (1988), the Japan Order of Culture (1988), the Albert Lasker Basic Medical Research Award (1989), the Kyoto Prize (1992), the Wolf Prize in Medicine (1995), the Jimenez Diaz Award (1995), and the Schering Prize (1995). He also served as a foreign member and honorary fellow of various academies, including the National Academies of Science, the Royal Society, l''Academie des Sciences, die Deutsche Akademie der Naturforscher Leopoldina, le Real Academia de Ciencias, the Asiatic Society, and the Japan Academy.¹