ABSTRACT
Background: Exposure to ionizing radiation during childhood is a well-established risk factor for thyroid cancer. However, the genetic mechanisms of radiation-associated carcinogenesis remain not fully understood. Methods: In this study, we used targeted next-generation sequencing and RNA-Seq to study 65 papillary thyroid cancers (PTCs) from patients in the Ukrainian-American cohort with measurement-based iodine-131 (I-131) thyroid doses received as a result of the Chernobyl accident. We fitted linear regression models to evaluate differences in distribution of risk factors for PTC according to type of genetic alteration and logistic regression models to evaluate the I-131 dose response. All statistical tests were two-sided. Results: Driver mutations were identified in 96.9% of these thyroid cancers, including point mutations in 26.2% and gene fusions in 70.8% of cases. Novel driver fusions such as POR-BRAF, as well as STRN-ALK fusions that have not been implicated in radiation-associated cancer before, were found. The mean I-131 dose in cases with point mutations was 0.2 Gy (range = 0.013-1.05 Gy), statistically significantly lower than 1.4 Gy (range = 0.009-6.15 Gy) for cases with fusions (P < .001). No driver point mutations were found in tumors from individuals who received more than 1.1 Gy of radiation. Relative to tumors with point mutations, the proportion of tumors with gene fusions increased with radiation dose, reaching 87.8% among individuals exposed to 0.3 Gy or higher. With a limited study sample size, the estimated odds ratio at 1 Gy was 20.01 (95% confidence interval = 2.57 to 653.02, P < .001). In addition, after controlling for I-131 dose, we found higher odds ratios for gene fusion-positive PTCs associated with several specific demographic and geographic features. Conclusions: Our data provide support for a link between I-131 thyroid dose and generation of carcinogenic gene fusions, the predominant mechanism of thyroid cancer associated with radiation exposure from the Chernobyl accident.
Subject(s)
Chernobyl Nuclear Accident , Gene Fusion , Iodine Radioisotopes/adverse effects , Mutation , Neoplasms, Radiation-Induced/genetics , Oncogene Proteins, Fusion/genetics , Thyroid Neoplasms/genetics , Adolescent , Adult , Anaplastic Lymphoma Kinase/genetics , Biomarkers, Tumor/genetics , Calmodulin-Binding Proteins/genetics , Carcinoma, Papillary/etiology , Carcinoma, Papillary/genetics , Carcinoma, Papillary/pathology , Child , Child, Preschool , Cohort Studies , Cytochrome P-450 Enzyme System/genetics , Female , Follow-Up Studies , High-Throughput Nucleotide Sequencing , Humans , Infant , Male , Membrane Proteins/genetics , Neoplasms, Radiation-Induced/etiology , Neoplasms, Radiation-Induced/pathology , Nerve Tissue Proteins/genetics , Prognosis , Proto-Oncogene Proteins B-raf/genetics , Radiation Dosage , Thyroid Neoplasms/etiology , Thyroid Neoplasms/pathology , Young AdultABSTRACT
OBJECTIVE: PTC-specific analysis identified novel fusions involving RET, BRAF, NTRK1, NTRK3, AGK and ALK genes in adults and pediatric PTCs. Although many novel fusions are PTC-specific events and, therefore, are ideal for diagnosis purposes, validation across additional and larger patient cohorts is essential for introducing these potential diagnostic or prognostic biomarkers into the clinical practice. As most of the BRAF, NTRK3 and ALK fusions were initially found in pediatric PTC or in more aggressive thyroid carcinomas, and there is a great disparity across population, in this study, we screened a large set of adult-sporadic PTC cases for the most prevalent kinase fusion lately described in the TCGA. DESIGN AND METHODS: The prevalence of the fusions was determined by RT-PCR in 71 classical PTC, 45 follicular variants of PTC (FVPTC), 19 follicular thyroid adenomas (FTAs) and 22 follicular thyroid carcinomas (FTCs). RESULTS: ETV6-NTRK3 was exclusively found in FVPTC, in both encapsulated and infiltrative variants, but was not found in FTAs and FTCs. STRN-ALK was found in both classical PTC and FVPTC. No AGK-BRAF fusion was identified in this series, endorsing that AGK-BRAF is a genetic event mainly associated with pediatric PTCs. CONCLUSIONS: The identification of kinase fusions in thyroid carcinomas helps to expand our knowledge about the landscape of oncogenic alterations in PTC. As ETV6-NTRK3 and STRN-ALK are recurrent and not identified in benign lesions, they can certainly help with diagnosis of thyroid nodules. Further analysis is needed to define if they can also be useful for prognosis and guiding therapy.
Subject(s)
Biomarkers, Tumor/metabolism , Calmodulin-Binding Proteins/metabolism , Carcinoma, Papillary/metabolism , Membrane Proteins/metabolism , Nerve Tissue Proteins/metabolism , Proto-Oncogene Proteins c-ets/metabolism , Receptor Protein-Tyrosine Kinases/metabolism , Receptor, trkC/metabolism , Repressor Proteins/metabolism , Thyroid Neoplasms/metabolism , Adult , Anaplastic Lymphoma Kinase , Biomarkers, Tumor/genetics , Calmodulin-Binding Proteins/genetics , Carcinoma, Papillary/diagnosis , Carcinoma, Papillary/genetics , Cohort Studies , Female , Humans , Male , Membrane Proteins/genetics , Middle Aged , Nerve Tissue Proteins/genetics , Protein Binding/physiology , Proto-Oncogene Proteins c-ets/genetics , Receptor Protein-Tyrosine Kinases/genetics , Receptor, trkC/genetics , Repressor Proteins/genetics , Thyroid Cancer, Papillary , Thyroid Neoplasms/diagnosis , Thyroid Neoplasms/genetics , Young Adult , ETS Translocation Variant 6 ProteinABSTRACT
OsWRKY47 is a divergent rice transcription factor belonging to the group II of the WRKY family. A transcriptomic analysis of the drought response of transgenic rice plants expressing P SARK ::IPT, validated by qPCR, indicated that OsWRKY47 expression was induced under drought stress in P SARK ::IPT plants. A PCR-assisted site selection assay (SELEX) of recombinant OsWRKY47 protein showed that the preferred sequence bound in vitro is (G/T)TTGACT. Bioinformatics analyses identified a number of gene targets of OsWRKY47; among these two genes encode a Calmodulin binding protein and a Cys-rich secretory protein. Using Oswrk47 knockout mutants and transgenic rice overexpressing OsWRKY47 we show that the transcription of these putative targets were regulated by OsWRKY47. Phenotypic analysis carried out with transgenic rice plants showed that Oswrky47 mutants displayed higher sensitivity to drought and reduced yield, while plants overexpressing OsWRKY47 were more tolerant.
Subject(s)
Oryza/genetics , Oryza/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Base Sequence , Binding Sites/genetics , Calmodulin-Binding Proteins/genetics , Calmodulin-Binding Proteins/metabolism , DNA, Plant/genetics , DNA, Plant/metabolism , Droughts , Gene Knockout Techniques , Genes, Plant , Molecular Sequence Data , Oryza/growth & development , Plants, Genetically Modified , Promoter Regions, Genetic , Stress, Physiological , TranscriptomeABSTRACT
Age-related macular degeneration (AMD) causes visual impairment in the elderly. In non-neovascular AMD, studies involving human subjects have suggested potential involvement of aberrant lipid metabolism. However, there have been no reports on gene expression patterns in animal models of non-neovascular AMD with abnormal lipid metabolism such as apolipoprotein E knockout and human apolipoprotein E2 transgenic mice. Transcriptome analysis was performed using retinal pigment epithelium cells of apoE knockout and apolipoprotein E2 mice using microarray analysis. C57BL/6, Rxrb, Pparbp, Vldlr, and Edf1, which are primarily related to lipid metabolism, were upregulated, while Tgfbr1 and Pdgfb, which are related to pathologic angiogenesis in AMD, were downregulated in both types of mice. Apolipoprotein E knockout and apolipoprotein E2 mice showed characteristic gene expression patterns in the transcriptome analysis of primary retinal pigment epithelium cells. These results suggest that specific genes associated with lipid metabolism and angiogenesis are involved in the pathogenesis and progression of AMD.
Subject(s)
Apolipoprotein E2/genetics , Epithelial Cells/metabolism , Retinal Pigment Epithelium/cytology , Transcriptome , Aged , Animals , Apolipoproteins E/genetics , Calmodulin-Binding Proteins/genetics , Calmodulin-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Disease Models, Animal , Down-Regulation , Humans , Lipid Metabolism , Lymphokines/genetics , Lymphokines/metabolism , Macular Degeneration/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microarray Analysis , PPAR-beta/genetics , PPAR-beta/metabolism , Platelet-Derived Growth Factor/genetics , Platelet-Derived Growth Factor/metabolism , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Receptor, Transforming Growth Factor-beta Type I , Receptors, LDL/genetics , Receptors, LDL/metabolism , Receptors, Transforming Growth Factor beta/genetics , Receptors, Transforming Growth Factor beta/metabolism , Up-RegulationABSTRACT
BACKGROUND: Hyalinizing clear cell carcinoma (HCCC) is a rare low-grade malignant tumor affecting the minor salivary glands; nasopharyngeal involvement is uncommon. METHODS AND RESULTS: A 38-year-old male patient presented with a 3.2 × 4.5 × 4.4 cm expansile mass obliterating the lumen of the nasopharynx and extending into the left nasal cavity. Histopathologically, the tumor was characterized by clear round to polygonal epithelial cells arranged in anastomosing trabeculae and solid nests. The stroma consisted of fibromyxoid connective tissue with areas of intense hyalinization and desmoplasia. Immunohistochemically, strong and diffuse reactivity for AE1/AE3, CK5/6, and p63 was observed. EWSR1 gene rearrangement was confirmed by fluorescence in situ hybridization. The diagnosis of nasopharyngeal HCCC was rendered. Surgical excision was performed along with adjuvant radiotherapy and chemotherapy. CONCLUSIONS: HCCC generally demonstrates good prognosis with low metastatic potential. Identification of EWSR1 gene disruption is usefulin discerning HCCC from other neoplasms with overlapping microscopic features.
Subject(s)
Adenocarcinoma, Clear Cell/genetics , Adenocarcinoma, Clear Cell/pathology , Calmodulin-Binding Proteins/genetics , Nasopharyngeal Neoplasms/genetics , Nasopharyngeal Neoplasms/pathology , RNA-Binding Proteins/genetics , Adult , Biomarkers, Tumor/analysis , Carcinoma , Gene Rearrangement , Humans , Hyalin/metabolism , Immunohistochemistry , In Situ Hybridization, Fluorescence , Male , Nasopharyngeal Carcinoma , RNA-Binding Protein EWSABSTRACT
Introducción. La hipertensión arterial es una enfermedad multifactorial influenciada por componentes genéticos y ambientales, cuya prevalencia varía entre grupos étnicos. Se han llevado a cabo numerosos estudios en genes de sistemas reguladores de la presión arterial, como el sistema renina-angiotensinaaldosterona, el sistema nervioso simpático, los factores endoteliales, y el balance de sodio, mostrando resultados incongruentes entre poblaciones. Objetivos. Evaluar el efecto de variantes en los genes AGT , AGTR1 , ACE , ADRB2 , DRD1 , ADD1 , ADD2 , ATP2B1 , TBXA2R y PTGS2 y del componente ancestral individual, sobre la hipertensión arterial y las cifras de presión arterial en una muestra de población antioqueña. Materiales y métodos. Se genotipificaron 107 casos y 253 controles para 12 variantes en los genes AGT , AGTR1 , ACE , ADRB2 , DRD1 , ADD1 , ADD2 , ATP2B1 , TBXA2R y PTGS2 , y para 20 marcadores informativos de ascendencia. Se evaluó la asociación de los polimorfismos y sus interacciones, y de la composición genética ancestral con hipertensión y cifras de presión arterial. Resultados. Los genes ADD2 , rs4852706 (OR=3,0; p=0,023); DRD1 , rs686 (OR=0,38; p=0,012) y ADRB2 , rs1042718 (OR=10,0; p=0,008); y combinaciones genotípicas de DRD1 con AGTR1 ; de AGT con ADD1 ; y de ADD1 con ATP2B1 y PTGS2 , se asociaron con hipertensión arterial. El componente ancestral amerindio se asoció con disminución en la presión arterial diastólica. Conclusiones. Variantes en los genes ADD2 , DRD1 , ADRB2 , AGTR1 , AGT , ADD1 , ATP2B1 y PTGS2 , individualmente o en su interacción, se encuentran asociadas con hipertensión. El componente ancestral amerindio tiene un efecto sobre las cifras de presión arterial.
Introduction: Hypertension is a multifactorial disease influenced by genetic and environmental components, with its prevalence varying across ethnic groups. Manifold studies on blood pressure regulatory system genes have been carried out -such as the renin-angiotensin-aldosterone system, the sympathetic nervous system, endothelial factor, and sodium balance-, but the results yielded were inconsistent among populations. Objectives: To evaluate the effect of both variants in genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R PTGS2, and the result of the individual ancestry component on hypertension and blood pressure levels among population in Antioquia. Methods and materials: 107 cases and 253 controls were genotyped for 12 variants on genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R y PTGS2, and for 20 ancestry informative markers. The association of polymorphisms and their interactions, and the association of ancestral genetic composition with hypertension and blood pressure levels were examined. Results: Genes ADD2, rs4852706 (OR=3.0; p=0.023); DRD1, rs686 (OR=0.38; p=0.012) and ADRB2, rs1042718 (OR=10.0; p=0.008); as well as genotypic combinations of DRD1 and AGTR1; AGT and ADD1; and ADD1 to ATP2B1 and PTGS2 were associated to hypertension. The Amerindian ancestry component was associated to some decrease in diastolic blood pressure. Conclusion: Variants on genes ADD2, DRD1, ADRB2, AGTR1, AGT, ADD1, ATP2B1 and PTGS2 individually or interacting, are associated to hypertension. The Amerindian ancestry component has an effect on blood pressure.
Subject(s)
Adult , Female , Humans , Male , Middle Aged , Hypertension/genetics , Angiotensinogen/genetics , Blood Pressure/genetics , Calmodulin-Binding Proteins/genetics , Colombia , /genetics , Peptidyl-Dipeptidase A/genetics , Plasma Membrane Calcium-Transporting ATPases/genetics , Receptor, Angiotensin, Type 1/genetics , /genetics , Receptors, Dopamine D1/genetics , /genetics , Risk FactorsABSTRACT
Considerable effort has been invested in searching for less invasive methods of diagnosing endometriosis. Previous studies have indicated altered levels of the CALD1 gene (encoding the protein caldesmon) in endometriosis. The aims of our study were to investigate whether average CALD1 expression and caldesmon protein levels are differentially altered in the endometrium and endometriotic lesions and to evaluate the performance of the CALD1 gene and caldesmon protein as potential biomarkers for endometriosis. Paired biopsies of endometrial tissue (eutopic endometrium) and endometriotic lesions (ectopic endometrium) were obtained from patients with endometriosis to evaluate CALD1 gene expression and caldesmon protein levels by real-time PCR and Western blot analysis, respectively. In addition, immunostaining for caldesmon to determine cellular localization was also performed. Endometrium from women without endometriosis was used as a control. Increased CALD1 expression and caldesmon levels were detected in the endometriotic lesions. The electrophoretic profile of caldesmon by Western blot analysis was clearly different between the control group (endometrium of women without endometriosis) and the group of women with endometriosis (eutopic endometrium and endometriotic lesions). Caldesmon expression as determined by immunostaining showed no variation among the cell types in endometriotic lesions and eutopic endometrium. Stromal cells marked positively in eutopic endometrium from control patients and in the endometriotic lesions. The presence of caldesmon in the endometrium of patients with and without endometriosis permitted diagnoses with 95% sensitivity (specificity 100%) and 100% sensitivity (specificity 100%) for the disease and for minimal to mild endometriosis in the proliferative phase of the menstrual cycle, respectively. In the secretory phase, minimal to mild endometriosis was detected with 90% sensitivity and 93.3% specificity. Caldesmon is a possible predictor of endometrial dysregulation in patients with endometriosis. A potential limitation of our study is the fact that other endometrial diseases were not excluded, and therefore prospective studies are needed to confirm the potential of caldesmon as a biomarker exclusively for endometriosis.
Subject(s)
Calmodulin-Binding Proteins/metabolism , Endometriosis/diagnosis , Endometrium/metabolism , Ovarian Diseases/diagnosis , Peritoneal Diseases/diagnosis , Adult , Biomarkers/metabolism , Calmodulin-Binding Proteins/genetics , Case-Control Studies , Endometriosis/genetics , Endometriosis/metabolism , Endometrium/pathology , Female , Humans , Ovarian Diseases/genetics , Ovarian Diseases/metabolism , Peritoneal Diseases/genetics , Peritoneal Diseases/metabolism , Predictive Value of Tests , Real-Time Polymerase Chain Reaction , Sensitivity and Specificity , Stromal Cells/metabolism , Stromal Cells/pathologyABSTRACT
The endothelial differentiation factor-1 (EDF-1) is a calmodulin binding protein that regulates calmodulin-dependent enzymes. In endothelial cells, this factor can form a protein complex with calmodulin. We analyzed the relationship between this factor and the members of calmodulin/calcineurin/nuclear factor of activated T-cells (NFAT) signaling pathway during adipogenesis of 3T3-F442A cells. We found that the expression of edf1 is upregulated during early adipogenesis, whereas that of calcineurin gene is lowered, suggesting that this pathway should be downregulated to allow for adipogenesis to occur. We also found that EDF-1 associates with calmodulin and calcineurin, most likely inactivating calcineurin. Our results showed that EDF-1 inactivates the calmodulin/calcineurin/NFAT pathway via sequestration of calmodulin, during early adipogenesis, and we propose a mechanism that negatively regulates the activation of calcineurin through a complex formation between EDF-1 and calmodulin. This finding raises the possibility that modulating this pathway might offer some alternatives to regulate adipose biology.
Subject(s)
Adipogenesis/physiology , Calcineurin/metabolism , Calmodulin-Binding Proteins/metabolism , Calmodulin/metabolism , NFATC Transcription Factors/metabolism , Adipogenesis/genetics , Animals , Calcineurin/genetics , Calcineurin Inhibitors , Calmodulin/genetics , Calmodulin-Binding Proteins/genetics , Cell Line , Down-Regulation , Mice , NFATC Transcription Factors/genetics , Signal TransductionABSTRACT
INTRODUCTION: Hypertension is a multifactorial disease influenced by genetic and environmental components, with its prevalence varying across ethnic groups. Manifold studies on blood pressure regulatory system genes have been carried out -such as the renin-angiotensin-aldosterone system, the sympathetic nervous system, endothelial factor, and sodium balance-, but the results yielded were inconsistent among populations. OBJECTIVES: To evaluate the effect of both variants in genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R PTGS2, and the result of the individual ancestry component on hypertension and blood pressure levels among population in Antioquia. METHODS AND MATERIALS: 107 cases and 253 controls were genotyped for 12 variants on genes AGT, AGTR1, ACE, ADRB2, DRD1, ADD1, ADD2, ATP2B1, TBXA2R y PTGS2, and for 20 ancestry informative markers. The association of polymorphisms and their interactions, and the association of ancestral genetic composition with hypertension and blood pressure levels were examined. RESULTS: Genes ADD2, rs4852706 (OR=3.0; p=0.023); DRD1, rs686 (OR=0.38; p=0.012) and ADRB2, rs1042718 (OR=10.0; p=0.008); as well as genotypic combinations of DRD1 and AGTR1; AGT and ADD1; and ADD1 to ATP2B1 and PTGS2 were associated to hypertension. The Amerindian ancestry component was associated to some decrease in diastolic blood pressure. CONCLUSION: Variants on genes ADD2, DRD1, ADRB2, AGTR1, AGT, ADD1, ATP2B1 and PTGS2 individually or interacting, are associated to hypertension. The Amerindian ancestry component has an effect on blood pressure.
Subject(s)
Hypertension/genetics , Adult , Angiotensinogen/genetics , Blood Pressure/genetics , Calmodulin-Binding Proteins/genetics , Colombia , Cyclooxygenase 2/genetics , Female , Humans , Male , Middle Aged , Peptidyl-Dipeptidase A/genetics , Plasma Membrane Calcium-Transporting ATPases/genetics , Receptor, Angiotensin, Type 1/genetics , Receptors, Adrenergic, beta-2/genetics , Receptors, Dopamine D1/genetics , Receptors, Thromboxane A2, Prostaglandin H2/genetics , Risk FactorsABSTRACT
Angiomatoid "malignant" fibrous histiocytoma is a rare sarcoma of low malignant potential that occurs most commonly in the extremities of children and young adults. Herein, we present a case of angiomatoid malignant fibrous histiocytoma with unusual histologic features arising in the mediastinum of an 80-year-old man. The tumor exhibited a reticular growth pattern and myxoid stroma. The tumor cells expressed epithelial membrane antigen and desmin. Cytogenetic analysis revealed the translocation t(2;22)(q33;q12). Molecular genetic analysis confirmed the rearrangement of the EWSR1 locus and the presence of the EWSR1/CREB1 fusion. This report expands the clinicopathologic spectrum of angiomatoid malignant fibrous histiocytoma and underscores the value of integrating morphologic, immunophenotypic, and molecular findings in the identification of its unusual morphologic variants.
Subject(s)
Histiocytoma, Malignant Fibrous/pathology , Mediastinal Neoplasms/pathology , Aged, 80 and over , Calmodulin-Binding Proteins/genetics , Chromosomes, Human, Pair 2/genetics , Chromosomes, Human, Pair 22/genetics , Cyclic AMP Response Element-Binding Protein/genetics , Cytogenetic Analysis , Histiocytoma, Malignant Fibrous/genetics , Humans , Male , Mediastinal Neoplasms/genetics , Oncogene Proteins, Fusion/genetics , RNA-Binding Protein EWS , RNA-Binding Proteins/genetics , Translocation, GeneticABSTRACT
BACKGROUND: Genetic and environmental factors determine the blood pressure (BP) response to changes in salt intake. Mutations in the alpha-adducin gene may be associated with hypertension and salt-sensitive hypertension. We investigated whether one alpha-adducin polymorphism, the Gly460Trp (G/T) variant, was associated with salt sensitivity, nitric oxide (NO) production; and cardiovascular risk factors in healthy adult normotensive Venezuelans. METHODS AND RESULTS: Subjects (n = 126) were screened for salt sensitivity. The alpha-Adducin polymorphism was tested in salt-sensitive (SS) and salt-resistant (SR) subjects. The G/T and G/G (wild gene) groups had similar BP levels. The G/T subjects had higher LDL-cholesterol (P =.01) and postload glucose AUC (P =.03) than G/G individuals. Genotype frequencies were not associated with BP or salt sensitivity (G/G, 38.1% SS and 61.9% SR vs G/T, 40.7% SS and 59.3% SR). Shifting from high salt to low salt diet produced comparable reductions in systolic BP and diastolic BP in G/T and G/G groups. The G/G and G/T groups excreted similar amounts of sodium on high and low salt diets. The SR subjects carrying the wild or the mutated gene showed no changes in NO metabolite excretion at different levels of salt intake. In SS subjects, the level of NO metabolite excretion was highly dependent on salt intake. A combination of SS and 460Trp mutation enhanced the sodium-dependent modulation of NO production. CONCLUSIONS: In normotensive Venezuelans, the alpha-adducin G/T polymorphism was not associated with BP, salt sensitivity, or with sodium excretion during sodium loading or restriction. G/T was associated with increased LDL-cholesterol and postload glucose levels. In SS, G/T was associated with greater salt-dependent modulation of NO excretion. However, this larger increase in NO excretion was not associated with a larger decrease in BP.
Subject(s)
Blood Pressure/drug effects , Calmodulin-Binding Proteins/genetics , Cardiovascular Diseases/etiology , Hispanic or Latino/genetics , Nitric Oxide/biosynthesis , Sodium Chloride, Dietary/pharmacology , Adult , Blood Pressure/genetics , Cardiovascular Diseases/ethnology , Humans , Nitric Oxide/genetics , Polymorphism, Genetic , Risk Factors , VenezuelaABSTRACT
A cDNA library of Plasmodium falciparum (Colombian strain FCB2) asexual stage was constructed in the lambda ZipLox vector. The lambda ZipLox library and a lambda ZAPII (Dd2 strain) were screened for genes coding for proteins that bind with or are related to calmodulin (CaM). Screening was accomplished with Hot start PCR assays and hybridization with radiolabeled probes. Actin I, CaM, glutamate synthase (GOGAT) and the three myosin clones--Pfmyo A, Pfmyo B and Pfmyo C--were identified. The clones coding for actin I, CaM and GOGAT were retrieved from the lambda ZipLox library, and the GOGAT and Pfmyo A clones from the lambda ZAP II library. The GOGAT clone contained an insert of 2,413 base pairs corresponding to 24.8% of the reported sequence. The Pfmyo A insert was 2,457 base pairs long, and represented the complete mRNA coding for this gene. Finally, the first report of a complete cDNA clone containing the P. falciparum myosin A is presented.
Subject(s)
Calmodulin-Binding Proteins/genetics , Gene Library , Glutamate Synthase/genetics , Myosins/genetics , Plasmodium falciparum/genetics , AnimalsABSTRACT
PC12 cell line is a cellular model to study neurite outgrowth and neurotransmitter release mechanisms. Molecular motors may be involved in these responses and myosin V could be a candidate to mediate these effects. Overlay experiments using [(125)I]-calmodulin showed that PC12 cells possess several calmodulin-binding proteins, some of them around 190-210 kDa. Western blots using affinity purified polyclonal antibodies raised against chicken brain myosin V revealed a component of 190 kDa, a molecular mass typical of myosin V. Furthermore, Northern blots using a myosin V probe also detected a transcript of around 12 kbp. Immunofluorescence cytochemistry demonstrated the localization of myosin V throughout the cytoplasm, in the neurites, growth cone tips, and with an intense asymmetrical perinuclear labeling. Western blot analyses of PC12 cellular extracts after FGF-2 and/or dibutyryl cAMP treatment revealed variations between myosin V and myosin II expression during neuronal differentiation. These results demonstrated the presence of myosin V in PC12 cells and also suggest a role for this motor molecule in the neuronal differentiation response in PC12 cells.
Subject(s)
Calmodulin-Binding Proteins/metabolism , Myosin Type V , Nerve Tissue Proteins/metabolism , Neurons/cytology , Animals , Blotting, Western , Bucladesine/pharmacology , Calmodulin/metabolism , Calmodulin-Binding Proteins/genetics , Cell Differentiation/drug effects , Cell Nucleus/drug effects , Cell Nucleus/metabolism , Cytoplasm/drug effects , Cytoplasm/metabolism , Fibroblast Growth Factor 2/pharmacology , Fluorescent Antibody Technique , Gene Expression Regulation/drug effects , Growth Cones/drug effects , Growth Cones/metabolism , Molecular Weight , Myosins/metabolism , Nerve Tissue Proteins/genetics , Neurites/drug effects , Neurites/metabolism , Neurons/drug effects , Neurons/metabolism , PC12 Cells , RNA, Messenger/analysis , RNA, Messenger/genetics , RatsABSTRACT
The perinuclear localization of myosin-V was investigated in a variety of cultured mammalian cells and in primary cultures of rat hippocampus. In all cells investigated, myosin-V immunoreactivity was associated with the centrosome. In interphase cells, myosin-V was found in pericentriolar material, and in both mother and daughter centrioles. These results were obtained by using two different fixation protocols with three different affinity-purified antibodies that recognized a single band in Western blots. During cell division, myosin-V staining was intense throughout the cytoplasm and was concentrated in a trail between migrating centrioles and in the mitotic spindle poles and spindle fibers. The centrosome targeting site was determined to reside within the globular tail domain, because centrosome association also was observed in living cells transfected with DNA encoding the tail domain fused with a green fluorescent protein tag, but not in cells transfected with the vector encoding green fluorescent protein by itself.