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1.
Jianbo Yang Varsha Singh Boyoung Cha Tian-E Chen Rafiquel Sarker Rakhilya Murtazina Shi Jin Nicholas C. Zachos George H. Patterson C. Ming Tse Olga Kovbasnjuk Xuhang Li Mark Donowitz 《The Journal of biological chemistry》2013,288(23):16960-16974
Na+/H+ exchanger regulatory factor (NHERF) proteins are a family of PSD-95/Discs-large/ZO-1 (PDZ)-scaffolding proteins, three of which (NHERFs 1-3) are localized to the brush border in kidney and intestinal epithelial cells. All NHERF proteins are involved in anchoring membrane proteins that contain PDZ recognition motifs to form multiprotein signaling complexes. In contrast to their predicted immobility, NHERF1, NHERF2, and NHERF3 were all shown by fluorescence recovery after photobleaching/confocal microscopy to be surprisingly mobile in the microvilli of the renal proximal tubule OK cell line. Their diffusion coefficients, although different among the three, were all of the same magnitude as that of the transmembrane proteins, suggesting they are all anchored in the microvilli but to different extents. NHERF3 moves faster than NHERF1, and NHERF2 moves the slowest. Several chimeras and mutants of NHERF1 and NHERF2 were made to determine which part of NHERF2 confers the slower mobility rate. Surprisingly, the slower mobility rate of NHERF2 was determined by a unique C-terminal domain, which includes a nonconserved region along with the ezrin, radixin, moesin (ERM) binding domain. Also, this C-terminal domain of NHERF2 determined its greater detergent insolubility and was necessary for the formation of larger multiprotein NHERF2 complexes. In addition, this NHERF2 domain was functionally significant in NHE3 regulation, being necessary for stimulation by lysophosphatidic acid of activity and increased mobility of NHE3, as well as necessary for inhibition of NHE3 activity by calcium ionophore 4-Br-. Thus, multiple functions of NHERF2 require involvement of an additional domain in this protein. A23187相似文献
2.
Murtazina DA Petukhov SP Rubtsov AM Storey KB Lopina OD 《Biochemistry. Biokhimii?a》2001,66(8):865-874
Although it was shown earlier that phosphorylation of Na,K-ATPase by cAMP-dependent protein kinase (PKA) occurs in intact cells, the purified enzyme in vitro is phosphorylated by PKA only after treatment by detergent. This is accompanied by an unfortunate side effect of the detergent that results in complete loss of Na,K-ATPase activity. To reveal the effect of Na,K-ATPase phosphorylation by PKA on the enzyme activity in vitro, the effects of different detergents and ligands on the stoichiometry of the phosphorylation and activity of Na,K-ATPase from duck salt glands (11-isoenzyme) were comparatively studied. Chaps was shown to cause the least inhibition of the enzyme. In the presence of 0.4% Chaps at 1 : 10 protein/detergent ratio in medium containing 100 mM KCl and 0.3 mM ATP, PKA phosphorylates serine residue(s) of the Na,K-ATPase with stoichiometry 0.6 mol Pi/mol of -subunit. Phosphorylation of Na,K-ATPase by PKA in the presence of the detergent inhibits the Na,K-ATPase. A correlation was found between the inclusion of Pi into the -subunit and the loss of activity of the Na,K-ATPase. 相似文献
3.
Dykhal IuI Mediantseva EP Murtazina NR Safina GR Budnikov GK Kalacheva NV 《Prikladnaia biokhimiia i mikrobiologiia》2003,39(6):630-636
A noncompetitive variant of immunochemical ribonuclease (RNase) determination has been developed, involving the use of Co(II) as a label. A variety of approaches to labeling the immunological reagent with the metal have been assessed. In the variant proposed, catalytic hydrogen release was used as a means of detecting the label, the amount of which was proportional to RNase concentration. Conditions making it possible to record catalytic hydrogen release fluxes were determined. In the presence of RNase, the electrocatalytic effect was maximum at a concentration of Co(II) in the ammoniac buffer, equal to 2 x 10(-4) M (pH 10.0). The dependence was linear in the range 4-2000 ng/ml RNase concentrations (threshold concentration, 2 ng/ml). 相似文献
4.
Murtazina R Kovbasnjuk O Zachos NC Li X Chen Y Hubbard A Hogema BM Steplock D Seidler U Hoque KM Tse CM De Jonge HR Weinman EJ Donowitz M 《The Journal of biological chemistry》2007,282(34):25141-25151
The multi-PDZ domain containing protein Na(+)/H(+) Exchanger Regulatory Factor 1 (NHERF1) binds to Na(+)/H(+) exchanger 3 (NHE3) and is associated with the brush border (BB) membrane of murine kidney and small intestine. Although studies in BB isolated from kidney cortex of wild type and NHERF1(-/-) mice have shown that NHERF1 is necessary for cAMP inhibition of NHE3 activity, a role of NHERF1 in NHE3 regulation in small intestine and in intact kidney has not been established. Here a method using multi-photon microscopy with the pH-sensitive dye SNARF-4F (carboxyseminaphthorhodafluors-4F) to measure BB NHE3 activity in intact murine tissue and use it to examine the role of NHERF1 in regulation of NHE3 activity. NHE3 activity in wild type and NHERF1(-/-) ileum and wild type kidney cortex were inhibited by cAMP, whereas the cAMP effect was abolished in kidney cortex of NHERF1(-/-) mice. cAMP inhibition of NHE3 activity in these two tissues is mediated by different mechanisms. In ileum, a protein kinase A (PKA)-dependent mechanism accounts for all cAMP inhibition of NHE3 activity since the PKA antagonist H-89 abolished the inhibitory effect of cAMP. In kidney, both PKA-dependent and non-PKA-dependent mechanisms were involved, with the latter reproduced by the effect on an EPAC (exchange protein directly activated by cAMP) agonist (8-(4-chlorophenylthio)-2'O-Me-cAMP). In contrast, the EPAC agonist had no effect in proximal tubules in NHERF1(-/-) mice. These data suggest that in proximal tubule, NHERF1 is required for all cAMP inhibition of NHE3, which occurs through both EPAC-dependent and PKA-dependent mechanisms; in contrast, cAMP inhibits ileal NHE3 only by a PKA-dependent pathway, which is independent of NHERF1 and EPAC. 相似文献
5.
Phospholipase CB3 (PLCB3) serine(1105) (S(1105)), a substrate for multiple protein kinases, represents a potential point of convergence of several signaling pathways in the myometrium. To explore this hypothesis, the regulation of PLCB3-S(1105) phosphorylation (P-S(1105)) was studied in immortalized and primary human myometrial cells. 8-[4-chlorophenylthio] (CPT)-cAMP and calcitonin gene-related peptide (CALCA) transiently increased P-S(1105). Relaxin also stimulated P-S(1105); this effect was partially blocked by the protein kinase A (PRKA) inhibitor, Rp-8-CPT-cAMPS. Oxytocin, which stimulates Galphaq-mediated pathways, also rapidly increased P-S(1105), as did prostaglandin F2alpha and ATP. Oxytocin-stimulated phosphorylation was blocked by protein kinase C (PRKC) inhibitor Go6976 and by pretreatment overnight with a phorbol ester. Cypermethrin, a PP2B phosphatase inhibitor, but not okadaic acid, a PP1/PP2A inhibitor, prolonged the effect of CALCA on P-S(1105), whereas the reverse was the case for the oxytocin-stimulated increase in P-S(1105). PLCB3 was the predominant PLC isoform expressed in the myometrial cells and PLCB3 short hairpin RNA constructs significantly attenuated oxytocin-stimulated increases in intracellular calcium. oxytocin-induced phosphatidylinositol (PI) turnover was inhibited by CPT-cAMP and okadaic acid, but was enhanced by pretreatment with Go6976. CPT-cAMP inhibited oxytocin-stimulated PI turnover in the presence of overexpressed PLCB3, but not overexpressed PLCB3-S(1105)A. These data demonstrate that both negative crosstalk from the cAMP/PRKA pathway and a negative feedback loop in the oxytocin/G protein/PLCB pathway involving PRKC operate in myometrial cells and suggest that different protein phosphatases predominate in mediating P-S(1105) dephosphorylation in these pathways. The integration of multiple signal components at the level of PLCB3 may be important to its function in the myometrium. 相似文献
6.
7.
Regulation and characterization of the Na+/H+ exchanger. 总被引:1,自引:0,他引:1
L Fliegel R Murtazina P Dibrov C Harris A Moor F A Fernandez-Rachubinski 《Biochimie et biologie cellulaire》1998,76(5):735-741
The Na+/H+ exchanger is a ubiquitous protein present in all mammalian cell types that functions to remove one intracellular H+ for one extracellular Na+. Several isoforms of the protein exist, which are referred to as NHE1 to NHE6 (for Na+/H+ exchanger one through six). The NHE1 protein was the first isoform cloned and studied in a variety of systems. This review summarizes recent papers on this protein, particularly those that have examined regulation of the protein and its expression and activity. 相似文献
8.
Zhuravlev BV Murtazina EP 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2002,88(6):715-722
Data by the authors, as well as from other laboratories, show that the intertrial responses correlated with accuracy of avoidance or feeding behaviour. Moreover our previously data demonstrated the definite changes of neuronal activity, heart rate and respiration during intertrial responses. In this study we investigated the time-course of intertrial response appearance, the pattern of neurophysiological parameters during intertrial periods, and the types of intertrial responses. Experiment 1 showed that different environmental stimuli influenced the level of intertrial responses and successfulness of the avoidance learning. In experiment 2, in which learning and extinction procedures were presented in rabbit passive-avoidance conditioning, two types of intertrial responses were observed; the first type repeated the pain reinforcement, the second one imitated the conditioned reaction of neuronal activity, heart rate, respiration, and moving. These investigations suggest that the processes of intertrial eliciting of avoidance effector programs may be one of the mechanisms of fixation in memory and play an important role in acquisition of more effective results. 相似文献
9.
Half-lives of plasma membrane Na+/H+ exchangers NHE1-3: plasma membrane NHE2 has a rapid rate of degradation 总被引:2,自引:0,他引:2
Cavet Megan E.; Akhter Shafinaz; Murtazina Rakhilya; Sanchez de Medina Fermin; Tse Chung-Ming; Donowitz Mark 《American journal of physiology. Cell physiology》2001,281(6):C2039
The Na+/H+ exchangers NHE2 and NHE3 areinvolved in epithelial Na+ and HCO absorption. To increase insights into the functions of NHE2 vs. NHE3,we compared their cellular processing with each other and with thehousekeeping isoform NHE1. Using biotinylated exchanger, we determinedthat the half-life of plasma membrane NHE2 was short (3 h) comparedwith that of NHE1 (24 h) and NHE3 (14 h) in both PS120 fibroblasts andCaco-2 cells. NHE2 transport and plasma membrane levels were reduced by3 h of Brefeldin A treatment, whereas NHE1 was unaffected. NHE2was degraded by the lysosomes but not proteosomes, as demonstrated byincreasing levels of endocytosed NHE2 protein after inhibition of thelysosomes, but not with proteosome inhibition. Unlike that of NHE3,basal NHE2 transport activity was not affected by phosphatidylinositol 3-kinase inhibition and did not appear to be localized in the juxtanuclear recycling endosome. Therefore, for NHE2, protein degradation and/or protein synthesis probably play important roles inits basal and regulated states. These results suggest fundamental differences in the cellular processing and trafficking of NHE2 andNHE3. These differences may underlie the specialized roles that theseexchangers play in epithelial cells. 相似文献
10.
A. R. Murtazina Y. O. Nikishina N. S. Bondarenko A. Ja. Sapronova M. V. Ugrumov 《Doklady. Biochemistry and biophysics》2016,466(1):74-76
Using the method of high performance liquid chromatography with electrochemical detection, the age dynamics of the content of noradrenaline (NA) in the brain, adrenal gland, and the organ of Zuckerkandl in prenatal (18th and 21st days of embryogenesis) and early postnatal (3, 7, 15, and 30th days) periods of development was studied. The potential contribution of these organs to the formation of physiologically active concentration of noradrenalin in the blood was also assessed. The results suggest that, during the development of the organism, the activity of the sources of noradrenaline in the general circulation changes, which gives a reason to assume the existence of humoral interaction between NA-producing organs in the perinatal period of ontogenesis. 相似文献