Second messengers and phosphoproteins最新文献

Activation of G-proteins induces Ca2+ oscillations with hyperpolarizing K+ currents in pancreatic beta-cells. 胰岛β细胞中g蛋白的激活诱导Ca2+振荡与超极化K+电流。

Second messengers and phosphoproteins Pub Date : 1992-01-01

P E Lund, B Hellman

引用次数: 0

Ca(2+)-induced persistent protein kinase C activation in rat hippocampal homogenates. Ca(2+)诱导大鼠海马匀浆持续蛋白激酶C激活。

Second messengers and phosphoproteins Pub Date : 1992-01-01

J S Sessoms, S J Chen, D M Chetkovich, C M Powell, E D Roberson, J D Sweatt, E Klann

{"title":"Ca(2+)-induced persistent protein kinase C activation in rat hippocampal homogenates.","authors":"J S Sessoms, S J Chen, D M Chetkovich, C M Powell, E D Roberson, J D Sweatt, E Klann","doi":"","DOIUrl":"","url":null,"abstract":"Protein kinase C (PKC) is thought to play an important role in neuronal function by mediating changes in synaptic strength. Specifically, it has been argued that persistent PKC activation underlies the maintenance of long-term potentiation (LTP) of synaptic transmission in the hippocampus, a model widely used to study mammalian learning and memory. Because the induction of LTP is known to be dependent upon Ca2+ influx into the postsynaptic neuron, we investigated Ca(2+)-dependent mechanisms that operate to elicit persistent PKC activation in the hippocampus. Hippocampal homogenates were incubated with Ca2+ for a brief period and subsequently assayed for persistent changes in basal (Ca(2+)-independent) PKC activity, using the selective PKC substrate neurogranin(28-43) (NG(28-43)). After Ca2+ incubation, basal PKC phosphorylation of NG(28-43) was increased and expression of the increased activity could be inhibited by PKC(19-36), a selective peptide inhibitor of PKC. These data indicate the presence of a persistently activated form of PKC in Ca(2+)-pretreated hippocampal homogenates. The persistently activated PKC was localized to the soluble fraction of homogenates. Generation of the soluble, persistently activated form of PKC was blocked by the calpain inhibitor, leupeptin, suggesting a proteolytic activation of PKC. Column chromatography and Western blots indicated the presence of PKM, a proteolytic fragment of PKC that is active in the absence of calcium, diacylglycerols, or phospholipid cofactors. Thus, Ca2+ induces proteolytic activation of PKC in hippocampal homogenates. This suggests that proteolytic activation is a plausible candidate as a mechanism underlying the persistent activation of PKC associated with LTP.","PeriodicalId":77384,"journal":{"name":"Second messengers and phosphoproteins","volume":"14 3","pages":"109-26"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12519571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inhibition of thrombin-induced platelet activation by dioctanoylglycerol pretreatment is not correlated with the 47 kDa protein phosphorylation. 二辛烷酰甘油预处理对凝血酶诱导的血小板活化的抑制作用与47 kDa蛋白磷酸化无关。

Second messengers and phosphoproteins Pub Date : 1992-01-01

M Ruzzene, M Francesconi, L Cavallini, L Battistella, R Deana

引用次数: 0

Protein kinase C phosphorylates both serine and threonine residues of the mRNA cap binding protein eIF-4E. 蛋白激酶C磷酸化mRNA帽结合蛋白eIF-4E的丝氨酸和苏氨酸残基。

Second messengers and phosphoproteins Pub Date : 1992-01-01

D W Haas, C H Hagedorn

引用次数: 0

Positively cooperative cAMP phosphodiesterase attenuates cellular cAMP responses. 正合作cAMP磷酸二酯酶减弱细胞cAMP反应。

Second messengers and phosphoproteins Pub Date : 1992-01-01

R Barber, T J Goka, R W Butcher

{"title":"Positively cooperative cAMP phosphodiesterase attenuates cellular cAMP responses.","authors":"R Barber, T J Goka, R W Butcher","doi":"","DOIUrl":"","url":null,"abstract":"We have shown that growth of S49 WT mouse lymphoma cells for 24 hr in 3 nM epinephrine produced very significant desensitization of subsequent cellular cAMP responses to challenges with higher concentrations of epinephrine. The effects of this long-term treatment (LTT) were obvious in intact cells and also when adenylate cyclase activity was measured in semi-purified membranes. Beta 2-adrenergic receptors (beta 2AR) were decreased by LTT, and the desensitization of adenylate cyclase was due at least in part to this down-regulation. When mouse L cells transfected with WT beta 2AR from hamster lung (L-WT beta 2AR cells) were subjected to LTT, the attenuation of adenylate cyclase in membranes was obvious, but the consequences of LTT on intact L-WT beta 2AR cells were highly equivocal. That is, when the effects of epinephrine on cellular cAMP levels were measured in LTT or control L-WT beta 2AR cells little desensitization was apparent. Further, cellular cAMP excursions in response to even very high concentrations of epinephrine were very small in control L-WT beta 2AR cells as compared to control S49 WT cells. Subsequent experiments have shown that L-WT beta 2AR cells possess a phosphodiesterase (PDE) which demonstrates marked positive cooperativity with cAMP with a Hill coefficient of 2. The EC50 for cAMP hydrolysis was approximately 30 nM in cell free preparations. cGMP was a positive allosteric effector of the L-WT beta 2AR cell PDE. Further, when cellular cAMP levels in intact L-WT beta 2AR cells were raised above a threshold by treatment with 0.5 microM forskolin and 2 mM IBMX with the epinephrine challenge, the effect of LLT became obvious in the intact cell system. These data demonstrate that cAMP responses to hormones are greatly decreased in systems where the predominant PDE demonstrates positive cooperativity for cAMP.","PeriodicalId":77384,"journal":{"name":"Second messengers and phosphoproteins","volume":"14 1-2","pages":"77-97"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12555007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Phospholamban-modulated Ca2+ transport in cardiac and slow twitch skeletal muscle sarcoplasmic reticulum. 磷蛋白在心脏和慢抽搐骨骼肌肌浆网中调节Ca2+运输。

Second messengers and phosphoproteins Pub Date : 1992-01-01

M A Movsesian, G L Morris, J H Wang, J Krall

{"title":"Phospholamban-modulated Ca2+ transport in cardiac and slow twitch skeletal muscle sarcoplasmic reticulum.","authors":"M A Movsesian, G L Morris, J H Wang, J Krall","doi":"","DOIUrl":"","url":null,"abstract":"The correlation between phospholamban and sarcoplasmic reticulum Ca(2+)-transporting ATPase levels and the magnitude of phospholamban-mediated stimulation of sarcoplasmic reticulum Ca2+ transport was examined in microsomes prepared from rabbit and canine cardiac, slow twitch and fast twitch skeletal muscle. Phospholamban was absent from microsomes prepared from fast twitch skeletal muscle but present at comparable levels in microsomes prepared from cardiac and slow twitch skeletal muscle. Levels of Ca(2+)-transporting ATPase were higher in microsomes prepared from slow twitch skeletal muscle than in microsomes prepared from cardiac muscle, however, and ratios of phospholamban to Ca(2+)-transporting ATPase were several fold greater in microsomes prepared from cardiac muscle than in microsomes prepared from slow twitch skeletal muscle. Stimulation of ATP-dependent Ca2+ transport following phosphorylation of phospholamban by cAMP-dependent protein kinase or incubation with anti-phospholamban monoclonal antibody was observed only in cardiac muscle microsomes. These observations indicate that phospholamban, while present in both cardiac and slow twitch skeletal muscle, may be involved in the hormonal regulation of sarcoplasmic reticulum Ca2+ transport only in the former, and that the lack of phospholamban-mediated stimulation of Ca2+ transport in slow twitch skeletal muscle sarcoplasmic reticulum may result from the lower ratio of phospholamban to Ca(2+)-transporting ATPase in this tissue.","PeriodicalId":77384,"journal":{"name":"Second messengers and phosphoproteins","volume":"14 3","pages":"151-61"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12518640","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of parathyroid hormone on rat renal calcium/calmodulin-dependent protein kinase II. 甲状旁腺激素对大鼠肾钙/钙调素依赖性蛋白激酶II的影响。

Second messengers and phosphoproteins Pub Date : 1992-01-01

R Nemani, N Wongsurawat, H J Armbrecht

引用次数: 0

Purine modulation of prostaglandin F2 alpha (PGF2 alpha)-induced premature luteolysis in vivo in nonpregnant sheep. 嘌呤调节前列腺素F2 α (PGF2 α)诱导未怀孕绵羊体内过早黄体溶解。

Second messengers and phosphoproteins Pub Date : 1992-01-01

C W Weems, Y S Weems, C N Lee, D L Vincent

{"title":"Purine modulation of prostaglandin F2 alpha (PGF2 alpha)-induced premature luteolysis in vivo in nonpregnant sheep.","authors":"C W Weems, Y S Weems, C N Lee, D L Vincent","doi":"","DOIUrl":"","url":null,"abstract":"In two separate experiments, control and PGF2 alpha-treated unilaterally ovariectomized ewes received vehicle or adenosine every four hours through an exteriorized catheter installed either to parafuse the ovarian vascular pedicle of the remaining ovary containing a corpus luteum (CL) or to infuse intrauterine ipsilateral to the remaining ovary with the CL. Infusions were given every four hours from day 7 through day 22 postestrus or until ewes returned to estrus. Chronic infusion of vehicle intrauterine or parafusion of the ovarian vascular pedicle with vehicle in PGF2 alpha-treated ewes shortened the interestrous interval compared to controls (P less than 0.05). However, chronic parafusion of the ovarian vascular pedicle with adenosine in PGF2 alpha-treated ewes prevented a PGF2 alpha-induced premature luteolysis (P less than 0.05) but not when adenosine was infused chronically intrauterine (P greater than 0.05). It is concluded that adenosine can block a PGF2 alpha-induced premature luteolysis in vivo and may have roles in regulation of luteal secretion of progesterone but it is probably not the embryonic antiluteolysin of early pregnancy in ewes.","PeriodicalId":77384,"journal":{"name":"Second messengers and phosphoproteins","volume":"14 1-2","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"12576332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Protein kinases associated with isolated mitotic spindles from mammalian cells: identification of a casein kinase II-like enzyme. 与哺乳动物细胞分离的有丝分裂纺锤体相关的蛋白激酶:酪蛋白激酶ii样酶的鉴定。

Second messengers and phosphoproteins Pub Date : 1992-01-01

J Díaz-Nido, J Avila

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Lipopolysaccharide stimulates phosphorylation of eukaryotic initiation factor-4F in macrophages and tumor necrosis factor participates in this event. 脂多糖刺激巨噬细胞真核起始因子- 4f的磷酸化，肿瘤坏死因子参与了这一过程。

Second messengers and phosphoproteins Pub Date : 1992-01-01

D W Haas, V L Shepherd, C H Hagedorn

引用次数: 0