Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
Add more filters

Country/Region as subject
Publication year range
1.
Prenat Diagn ; 43(8): 1028-1035, 2023 07.
Article in English | MEDLINE | ID: mdl-37170409

ABSTRACT

OBJECTIVE: To assess the perinatal outcome after fetal reduction in complicated monochorionic (MC) twin pregnancies by comparing different techniques. METHODS: A retrospective cohort study at a national referral center comparing data between four techniques: interstitial laser coagulation, radiofrequency ablation (RFA), fetoscopic laser coagulation (FLC) and bipolar cord coagulation (BCC). The primary outcome was the mortality of the co-twins. Secondary outcomes were preterm pre-labor rupture of membranes (PPROM), gestational age at delivery and neonatal morbidity. RESULTS: 259 MC twin pregnancies underwent selective fetal reduction: 29 IL, 64 RFA, 85 FLC and 81 BCC. The perinatal mortality rate was 29% and fetal demise of the co-twins occurred in 19%. The lowest mortality rate was seen after BCC (17%, p = 0.012). PPROM occurred in 18% patients without significant differences between techniques. The mean gestational age at delivery in liveborn children was 35 weeks and did not differ between techniques. Severe cerebral injury and neonatal morbidity were reported in 4% and 14%, respectively, without significant differences between techniques. CONCLUSIONS: Selective fetal reductions in MC twins are precarious procedures with an increased risk of perinatal mortality of the co-twins. Our results show the lowest mortality rates after BCC. However, high PPROM rates were seen irrespective of the technique.


Subject(s)
Fetal Membranes, Premature Rupture , Pregnancy, Twin , Female , Humans , Infant , Infant, Newborn , Pregnancy , Fetal Membranes, Premature Rupture/etiology , Gestational Age , Pregnancy Outcome/epidemiology , Pregnancy Reduction, Multifetal/adverse effects , Retrospective Studies , Twins, Monozygotic
2.
Tijdschr Psychiatr ; 59(6): 366-371, 2017.
Article in Dutch | MEDLINE | ID: mdl-28613369

ABSTRACT

Monoamine oxidase (mao) inhibitors are antidepressants with potentially severe side-effects. For this reason, the registration of this drug was suspended for some time when safer alternatives became available. However, mao inhibitors can be very effective in cases where depression has proved to be treatment resistant. Consequently, last year tranylcypromine was re-registered for use in the Netherlands. Since mao inhibitors have been used only sporadically in the Netherlands over the last few years, health professionals have only limited knowledge about the side-effects. On the basis of a recent case, we discuss the two most important side-effects of using mao inhibitors, namely hypertension and orthostatic hypotension. We discuss the possible causes and suggest ways on which these two side-effects can be prevented, or treated, should they arise.


Subject(s)
Antidepressive Agents/adverse effects , Hypertension/chemically induced , Hypotension, Orthostatic/chemically induced , Monoamine Oxidase Inhibitors/adverse effects , Antidepressive Agents/therapeutic use , Female , Humans , Hypertension/prevention & control , Hypotension, Orthostatic/prevention & control , Middle Aged , Monoamine Oxidase Inhibitors/therapeutic use
3.
Diabet Med ; 31(11): 1350-6, 2014 Nov.
Article in English | MEDLINE | ID: mdl-24958070

ABSTRACT

AIMS: To investigate whether polymorphisms in SLC6A20 are associated with susceptibility to Type 2 diabetes. METHODS: In the Rotterdam Study, a prospective, population-based cohort (n = 5974), 22 tagging polymorphisms with minor allele frequencies>0.05 across SLC6A20 were studied. Replication studies were performed in an independent Dutch case-control study (DiaGene-Rotterdam Study 2 n = 3133), and in a Chinese Han case-control population (n = 2279). A meta-analysis of the results was performed. RESULTS: In the Rotterdam study, the minor alleles of rs13062383, rs10461016 and rs2286489 increased the risk of Type 2 diabetes (hazard ratio 1.37, 95% CI 1.15-1.63, hazard ratio 1.30 95% CI 1.09-1.54 and hazard ratio 1.20, 95% CI 1.07-1.35, respectively). In the DiaGene/Rotterdam Study 2, the A allele of rs13062383 increased the risk of Type 2 diabetes (odds ratio 1.45, 95% CI 1.19-1.76). In the Chinese Han study, the rs13062383 A allele also increased the risk of Type 2 diabetes (odds ratio 1.21, 95% CI 1.03-1.42). Meta-analysis showed a highly significant association of rs13062383 with Type 2 diabetes (odds ratio 1.35, 95% CI 1.21-1.47; P = 3.3 × 10⁻8). CONCLUSIONS: In conclusion, rs13062383 in SLC6A20 increased the susceptibility to Type 2 diabetes in populations with different genetic backgrounds.


Subject(s)
Diabetes Mellitus, Type 2/genetics , Membrane Transport Proteins/genetics , Polymorphism, Single Nucleotide , Adult , Aged , Alleles , Asian People , Case-Control Studies , China , Cohort Studies , Diabetes Mellitus, Type 2/metabolism , Female , Follow-Up Studies , Gene Frequency , Genetic Association Studies , Genetic Predisposition to Disease , Humans , Introns , Male , Membrane Transport Proteins/metabolism , Middle Aged , Netherlands , Prospective Studies , White People
4.
Sci Eng Ethics ; 19(3): 963-81, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23229374

ABSTRACT

In their 2007 paper, Swierstra and Rip identify characteristic tropes and patterns of moral argumentation in the debate about the ethics of new and emerging science and technologies (or "NEST-ethics"). Taking their NEST-ethics structure as a starting point, we considered the debate about tissue engineering (TE), and argue what aspects we think ought to be a part of a rich and high-quality debate of TE. The debate surrounding TE seems to be predominantly a debate among experts. When considering the NEST-ethics arguments that deal directly with technology, we can generally conclude that consequentialist arguments are by far the most prominently featured in discussions of TE. In addition, many papers discuss principles, rights and duties relevant to aspects of TE, both in a positive and in a critical sense. Justice arguments are only sporadically made, some "good life" arguments are used, others less so (such as the explicit articulation of perceived limits, or the technology as a technological fix for a social problem). Missing topics in the discussion, at least from the perspective of NEST-ethics, are second "level" arguments-those referring to techno-moral change connected to tissue engineering. Currently, the discussion about tissue engineering mostly focuses on its so-called "hard impacts"-quantifiable risks and benefits of the technology. Its "soft impacts"-effects that cannot easily be quantified, such as changes to experience, habits and perceptions, should receive more attention.


Subject(s)
Ethical Theory , Science/ethics , Social Justice , Social Responsibility , Technology/ethics , Tissue Engineering/ethics , Human Rights , Humans , Moral Obligations , Quality of Life
5.
Mol Biol (Mosk) ; 47(5): 717-30, 2013.
Article in Russian | MEDLINE | ID: mdl-25509344

ABSTRACT

For their protection from host cell immune defense, intracellular eukaryotic parasites developed a variety of mechanisms, including secretion systems III and IV which inject bacterial effectors directly into eukaryotic cells. These effectors may be posttranslational modified by host cell machinery and may function inside the host cell. Recently, to the list of possible posttranslational modifications of bacterial proteins the prenylation was added. In this work we describe current state of the knowledge about the prenylation of eukaryotic and prokaryotic proteins and its inhibitors. The bioinformatics analyses suggest possibility of prenylation for a number of Francisella genus proteins.


Subject(s)
Bacteria/metabolism , Eukaryota/metabolism , Host-Parasite Interactions/immunology , Protein Prenylation/genetics , Protein Processing, Post-Translational , Bacteria/genetics , Bacterial Proteins/metabolism , Bacterial Secretion Systems/immunology , Computational Biology/methods , Eukaryota/genetics , Francisella/immunology , Francisella/metabolism
6.
J Cyst Fibros ; 22(3): 577-579, 2023 May.
Article in English | MEDLINE | ID: mdl-36693768

ABSTRACT

Cystic fibrosis (CF) is incurable and chronic, causing severe multisystemic damage and long-term complications. The most prominent extrapulmonary long-term complication is CF-related diabetes, which is the most reported form of diabetes in individuals with cystic fibrosis. Here we present the first case of an individual with cystic fibrosis who developed type 2 diabetes due to obesity rather than CF-related diabetes. The type 2 diabetes went into remission due to extreme weight loss after gastric bypass surgery. To our knowledge, this case is also the first report describing the effect of bariatric surgery in a patient with CF. This case demonstrates that patients with CF may present with type 2 diabetes instead of CF-related diabetes. Differential diagnosis of these two types of diabetes is essential for optimal treatment and quality of life.


Subject(s)
Bariatric Surgery , Cystic Fibrosis , Diabetes Mellitus, Type 2 , Humans , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/diagnosis , Cystic Fibrosis/complications , Cystic Fibrosis/diagnosis , Cystic Fibrosis/surgery , Quality of Life , Bariatric Surgery/adverse effects , Obesity/complications
7.
Diabetologia ; 54(6): 1360-7, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21373834

ABSTRACT

AIMS/HYPOTHESIS: An APOC3 promoter haplotype has been previously associated with type 1 diabetes. In this population-based study, we investigated whether APOC3 polymorphisms increase type 2 diabetes risk and need for insulin treatment in lean participants. METHODS: In the Rotterdam Study, a population-based prospective cohort (n = 7,983), Cox and logistic regression models were used to analyse the associations and interactive effects of APOC3 promoter variants (-482C > T, -455T > C) and BMI on type 2 diabetes risk and insulin treatment. Analyses were followed by replication in an independent case-control sample (1,817 cases, 2,292 controls) and meta-analysis. RESULTS: In lean participants, the -482T allele was associated with increased risk of prevalent and incident type 2 diabetes: OR -482CT 1.47 (95% CI 1.13-1.92), -482TT 1.40 (95% CI 0.83-2.35), p = 0.009 for trend; HR -482CT 1.35 (95% CI 0.96-1.89), -482TT 1.68 (95% CI 0.91-3.1), p = 0.03 for trend, respectively. These results were confirmed by replication. Meta-analysis was highly significant (-482T meta-analysis p = 1.1 × 10(-4)). A borderline significant interaction was observed for insulin use among participants with type 2 diabetes (-482CT*BMI p = 0.06, -455TC*BMI p = 0.02). CONCLUSIONS/INTERPRETATION: At a population-based level, the influence of APOC3 promoter variants on type 2 diabetes risk varies with the level of adiposity. Lean carriers of the -482T allele had increased type 2 diabetes risk, while such an effect was not observed in overweight participants. Conversely, in overweight participants the -455C allele seemed protective against type 2 diabetes. The interaction of the variants with need for insulin treatment may indicate beta cell involvement in lean participants. Our findings suggest overlap in the genetic backgrounds of type 1 diabetes and type 2 diabetes in lean patients.


Subject(s)
Apolipoprotein C-III/genetics , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/genetics , Genetic Predisposition to Disease/genetics , Insulin/therapeutic use , Polymorphism, Single Nucleotide/genetics , Thinness/physiopathology , Aged , Aged, 80 and over , Alleles , Case-Control Studies , Cohort Studies , Diabetes Mellitus, Type 2/physiopathology , Female , Haplotypes , Humans , Hypoglycemic Agents/therapeutic use , Logistic Models , Male , Middle Aged , Netherlands , Prevalence , Promoter Regions, Genetic/genetics , Prospective Studies , Risk Factors
8.
Atheroscler Plus ; 44: 43-50, 2021 Oct.
Article in English | MEDLINE | ID: mdl-36644668

ABSTRACT

Background and aims: High-density lipoproteins (HDL) of patients with type 2 diabetes mellitus (T2DM) have impaired anti-inflammatory activities. The anti-inflammatory activity of HDL has been determined ex vivo after isolation by different methods from blood mostly obtained after overnight fasting. We first determined the effect of the HDL isolation method, and subsequently the effect of food intake on the anti-inflammatory function of HDL from T2DM patients. Methods: Blood was collected from healthy controls and T2DM patients after an overnight fast, and from T2DM patients 3 h after breakfast (n = 17 each). HDL was isolated by a two-step density gradient ultracentrifugation in iodixanol (HDLDGUC2), by sequential salt density flotation (HDLSEQ) or by PEG precipitation (HDLPEG). The anti-inflammatory function of HDL was determined by the reduction of the TNFα-induced expression of VCAM-1 in human coronary artery endothelial cells (HCAEC) and retinal endothelial cells (REC). Results: HDL isolated by the three different methods from healthy controls inhibited TNFα-induced VCAM-1 expression in HCAEC. With apoA-I at 0.7 µM, HDLDGUC2 and HDLSEQ were similarly effective (16% versus 14% reduction; n = 3; p > 0.05) but less effective than HDLPEG (28%, p < 0.05). Since ultracentrifugation removes most of the unbound plasma proteins, we used HDLDGUC2 for further experiments. With apoA-I at 3.2 µM, HDL from fasting healthy controls and T2DM patients reduced TNFα-induced VCAM-1 expression in HCAEC by 58 ± 13% and 51 ± 20%, respectively (p = 0.35), and in REC by 42 ± 13% and 25 ± 18%, respectively (p < 0.05). Compared to preprandial HDL, postprandial HDL from T2DM patients reduced VCAM-1 expression by 56 ± 16% (paired test: p < 0.001) in HCAEC and by 34 ± 13% (paired test: p < 0.05) in REC. Conclusions: The ex vivo anti-inflammatory activity of HDL is affected by the HDL isolation method. Two-step ultracentrifugation in an iodixanol gradient is a suitable method for HDL isolation when testing HDL anti-inflammatory function. The anti-inflammatory activity of HDL from overnight fasted T2DM patients is significantly impaired in REC but not in HCAEC. The anti-inflammatory function of HDL is partly restored by food intake.

9.
J Clin Endocrinol Metab ; 94(2): 428-33, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19017754

ABSTRACT

CONTEXT: A 56-yr-old woman presented with acromegaly, a pulmonary mass, and elevated levels of GHRH, GH, and IGF-I. Histological examination revealed a bronchial carcinoid with positive staining for GHRH. Somatostatin analogs (SAs) can play an important role in the treatment of neuroendocrine tumors, dependent on the somatostatin receptor subtype (sst) expression pattern. The sst pattern in bronchial carcinoids and effects of SAs have not been extensively investigated, particularly not for the recently developed universal SA SOM230 (Pasireotide) that has high affinity for sst1, 2, 3, and 5. OBJECTIVE: Our objective was to investigate the in vivo response of a GHRH-producing bronchial carcinoid to octreotide (OCT), its sst-expression profile, and in vitro responses to different SAs, including SOM230. METHODS: In vivo, 50 microg OCT was administered, and plasma GH and GHRH responses were determined. In vitro, the expression of ssts was analyzed by quantitative PCR. Furthermore, the effects of SOM230 and OCT on GHRH secretion were evaluated in primary cell cultures of the carcinoid tissue. RESULTS: In vivo, OCT administration fully suppressed GH and GHRH levels. In vitro, sst1 mRNA was most abundant, followed by sst2 and sst5. Both SOM230 and OCT inhibited GHRH production dose dependently (SOM230 100 nm vs. control, P = 0.01; OCT 110 nm vs. control, P = 0.05). CONCLUSIONS: In this case of a GHRH-producing bronchial carcinoid, we demonstrated that SOM230 was a potent inhibitor of GHRH production in vitro and was at least equally potent compared with OCT. Therefore, SOM230 may be a potential therapeutic agent to control GHRH secretion in ectopic acromegaly.


Subject(s)
Bronchial Neoplasms/drug therapy , Carcinoid Tumor/drug therapy , Growth Hormone-Releasing Hormone/metabolism , Somatostatin/analogs & derivatives , Acromegaly/drug therapy , Acromegaly/etiology , Bronchial Neoplasms/complications , Bronchial Neoplasms/metabolism , Carcinoid Tumor/complications , Carcinoid Tumor/metabolism , Female , Hormones, Ectopic/metabolism , Humans , Middle Aged , Somatostatin/pharmacology , Somatostatin/therapeutic use , Treatment Outcome , Tumor Cells, Cultured
10.
J Hum Hypertens ; 29(2): 82-6, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25031086

ABSTRACT

Proprotein convertase subtilisin/kexin-type 1 (PCSK1) activates precursors pro-opiomelanocortin (POMC), proinsulin and prorenin. We investigated if common variants in the PCSK1 gene influence blood pressure and risk of hypertension. Additionally, we investigated the risk of obesity and type 2 diabetes (T2D). In the Rotterdam Study (RS1), a prospective, population-based cohort (n=5974), four single-nucleotide polymorphisms (rs10515237, rs6232, rs436321 and rs3792747) in PCSK1 were studied. Linear and Cox regression models served to analyze associations between variants and end points. Replication was performed in the Rotterdam Study Plus1 (RSPlus1, n=1895). Rs436321 was significantly associated with systolic and diastolic blood pressure and risk of hypertension (odds ratio (OR): 1.1-1.3; P<0.05 in both populations). Rs6232 was associated with body mass index (BMI) (P=0.007 and P=0.04 in RS1 and RSPlus1, respectively). In RSPlus1, heterozygotes for rs6232 had 1.5 times higher risk of obesity (OR: 1.46; 95% confidence interval: 1.04-2.03; P=0.03). We did not find significant associations of PCSK1 with fasting insulin levels and T2D. We found an association of genetic variation in the PCSK1 gene with blood pressure and hypertension. Furthermore, we replicated the association of PCSK1 with BMI and obesity. No relationship was found between PCSK1 variants and fasting insulin levels and T2D. Our findings suggest that genetic variation in PCSK1 may contribute to, at least, some of these interrelated disorders.


Subject(s)
Blood Pressure/genetics , Body Mass Index , Hypertension/genetics , Proprotein Convertase 1/genetics , Aged , Diabetes Mellitus, Type 2/genetics , Female , Genetic Predisposition to Disease , Genotype , Humans , Insulin/blood , Male , Middle Aged , Obesity/genetics , White People/genetics
12.
Neth J Med ; 73(7): 308-9, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26314712
14.
Curr Med Res Opin ; 25(1): 93-101, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19210142

ABSTRACT

OBJECTIVE: Adiponectin, secreted by adipose tissue, plays an important role in lipoprotein metabolism and also affects carbohydrate and insulin pathways. We studied the effects of atorvastatin treatment on plasma adiponectin and high density cholesterol (HDL) levels in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: In the 'Diabetes Atorvastatin Lipid Intervention' (DALI) study, a randomized placebo-controlled study on the effects of atorvastatin treatment in 194 patients with type 2 diabetes and mildly elevated plasma triglycerides, adiponectin levels, lipoproteins, cholesteryl ester transfer protein (CETP) mass, as well as postheparin lipoprotein lipase (LPL) and hepatic lipase (HL) activities were assessed at baseline and after 6 months of treatment (placebo, 10 mg or 80 mg atorvastatin). RESULTS: At baseline, plasma adiponectin levels were positively associated with HDL cholesterol (r = 0.40, p < 0.001), and apoA-I (r = 0.38, p < 0.001) in both males and females. Adiponectin was negatively associated with triglycerides (r = -0.26, p < 0.001) in males as well as in females. Atorvastatin treatment had no effect on plasma adiponectin levels. However, adiponectin levels at baseline significantly predicted the effect of atorvastatin treatment on HDL-cholesterol (p = 0.007), i.e. patients with the highest baseline plasma adiponectin concentration (tertile 3) displayed the largest increase in plasma HDL cholesterol during treatment (8-10%), while the HDL-cholesterol increase in tertile 1 was almost negligible (1-3%). CONCLUSION: In this study, high baseline plasma adiponectin levels significantly affect the HDL-cholesterol response to atorvastatin treatment in patients with type 2 diabetes and therefore may play a role in defining future treatment strategy.


Subject(s)
Adiponectin/blood , Anticholesteremic Agents/therapeutic use , Cholesterol, HDL/blood , Diabetes Mellitus, Type 2/blood , Heptanoic Acids/therapeutic use , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Pyrroles/therapeutic use , Atorvastatin , Double-Blind Method , Female , Humans , Male , Placebos
15.
Diabetologia ; 51(8): 1423-8, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18496666

ABSTRACT

AIMS/HYPOTHESIS: Retinol-binding protein 4 (RBP4), originally known for retinol transport, was recently identified as an adipokine affecting insulin resistance. The RBP4 -803GA promoter polymorphism influences binding of hepatic nuclear factor 1alpha and is associated with type 2 diabetes in case-control studies. We hypothesised that the RBP4 -803GA polymorphism increases type 2 diabetes risk at a population-based level. In addition, information on retinol intake and plasma vitamin A levels enabled us to explore the possible underlying mechanism. METHODS: In the Rotterdam Study, a prospective, population-based, follow-up study, the -803GA polymorphism was genotyped. In Cox proportional hazards models, associations of the -803GA polymorphism and retinol intake with type 2 diabetes risk were examined. Moreover, the interaction of the polymorphism with retinol intake on type 2 diabetes risk was assessed. In a subgroup of participants the association of the polymorphism and vitamin A plasma levels was investigated. RESULTS: Homozygous carriers of the -803A allele had increased risk of type 2 diabetes (HR 1.83; 95% CI 1.26-2.66). Retinol intake was not associated with type 2 diabetes risk and showed no interaction with the RBP4 -803GA polymorphism. Furthermore, there was no significant association of the polymorphism with plasma vitamin A levels. CONCLUSIONS/INTERPRETATION: Our results provide evidence that homozygosity for the RBP4 -803A allele is associated with increased risk of type 2 diabetes in the Rotterdam population. This relationship was not clearly explained by retinol intake and vitamin A plasma levels. Therefore, we cannot differentiate between a retinol-dependent or -independent mechanism of this RBP4 variant.


Subject(s)
Diabetes Mellitus, Type 2/epidemiology , Polymorphism, Genetic , Promoter Regions, Genetic , Retinol-Binding Proteins, Plasma/genetics , Aged , Blood Pressure , Body Mass Index , Body Size , Diabetes Mellitus, Type 2/genetics , Female , Genotype , Hepatocyte Nuclear Factor 1-alpha/metabolism , Humans , Hypertension/epidemiology , Hypertension/genetics , Insulin Resistance/genetics , Liver/metabolism , Male , Netherlands , Risk Factors
16.
Biophys J ; 91(8): 2833-43, 2006 Oct 15.
Article in English | MEDLINE | ID: mdl-16877514

ABSTRACT

Bistability in the lac operon of Escherichia coli has been widely studied, both experimentally and theoretically. Experimentally, bistability has been observed when E. coli is induced by an artificial, nonmetabolizable, inducer. However, if the lac operon is induced with lactose, the natural inducer, bistability has not been demonstrated. We derive an analytical expression that can predict the occurrence of bistability both for artificial inducers and lactose. We find very different conditions for bistability in the two cases. Indeed, for artificial inducers bistability is predicted, but for lactose the condition for bistability is much more difficult to satisfy. Moreover, we demonstrate that in silico evolution of the lac operon generates an operon that avoids bistability with respect to lactose, but does exhibit bistability with respect to artificial inducers. The activity of this evolved operon strikingly resembles the experimentally observed activity of the operon. Thus our computational experiments suggest that the wild-type lac operon, which regulates lactose metabolism, is not a bistable switch. Nevertheless, for engineering purposes, this operon can be used as a bistable switch with artificial inducers.


Subject(s)
Computer Simulation , Lac Operon , Lactose/metabolism , Models, Genetic , Escherichia coli/genetics , Escherichia coli/metabolism , Gene Expression Regulation, Bacterial , Glucose/metabolism
17.
Biochem J ; 326 ( Pt 1): 271-7, 1997 Aug 15.
Article in English | MEDLINE | ID: mdl-9337879

ABSTRACT

Chromaffin cells, which secrete catecholamines in response to acetylcholine, express high levels of the Src-family tyrosine kinases. These kinases contain protein-protein interaction domains which bind signal transduction proteins that participate in a variety of cellular processes. To determine if signalling proteins bind c-Src in chromaffin cells, we examined c-Src immunocomplexes for co-precipitating proteins. We discovered a phosphotyrosine phosphatase (PTPase; EC 3.1.3.48) activity which associates with specific subcellular pools of c-Src in vivo and which preferentially binds the SH2 (Src homology 2) domain of c-Src in vitro. Known PTPases were not identified by blotting of c-Src immunocomplexes with a panel of anti-PTPase antibodies, suggesting that the PTPase may be a novel family member. The c-Src-PTPase complex is enriched in the plasma membrane fraction and exists in several large complexes, as revealed by gel-filtration analysis. This PTPase activity is altered rapidly following stimulation by secretagogues, decreasing within 30 s and returning to basal levels by 60 s of stimulation. Both the subcellular localization and rapid activity changes suggest that the c-Src-associated PTPase may function in early signalling events emanating from the nicotinic acetylcholine receptor. In support of this is the co-precipitation of a PTPase activity with the nicotinic acetylcholine receptor and co-chromatography of this receptor with one or the c-Src-PTPase complexes.


Subject(s)
Adrenal Medulla/enzymology , Chromaffin Cells/enzymology , Multienzyme Complexes/metabolism , Protein Tyrosine Phosphatases/metabolism , Protein-Tyrosine Kinases/metabolism , Adrenal Medulla/chemistry , Adrenal Medulla/cytology , Animals , Antibodies, Monoclonal , Blotting, Western , CSK Tyrosine-Protein Kinase , Cattle , Cells, Cultured , Chromaffin Cells/chemistry , Multienzyme Complexes/immunology , Multienzyme Complexes/isolation & purification , Peptide Mapping , Protein Tyrosine Phosphatases/immunology , Protein Tyrosine Phosphatases/isolation & purification , Protein-Tyrosine Kinases/immunology , Protein-Tyrosine Kinases/isolation & purification , Subcellular Fractions/chemistry , Subcellular Fractions/enzymology , src-Family Kinases
SELECTION OF CITATIONS
SEARCH DETAIL