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Katahira M, Imai S, Ono S, Moriura S. Estimating Triglyceride Levels Using Total Cholesterol, Low-Density Lipoprotein Cholesterol, and High-Density Lipoprotein Cholesterol Levels: A Cross-Sectional Study. Metab Syndr Relat Disord 2023; 21:327-334. [PMID: 37405724 DOI: 10.1089/met.2023.0045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2023] Open
Abstract
Objective: Triglyceride (TG) levels are affected by food intake, and the cutoff values for nonfasting TG levels vary. This study aimed to calculate fasting TG levels based on total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) levels. Methods: Multiple regression analysis was performed to determine estimated triglyceride (eTG) levels using data from 39,971 participants divided into six groups based on non-high-density lipoprotein cholesterol (nHDL-C) levels (<100, <130, <160, <190, <220, and ≥220 mg/dL). Results: Provided that fasting TG and eTG levels ≥150 mg/dL were positive and those <150 mg/dL were negative, the three groups (nHDL-C levels <100, <130, and <160 mg/dL) consisting of 28,616 participants had a false-positive rate of <5%. The coefficient and constant terms in the formula for the eTG in groups with nHDL-C levels <100, <130, and <160 mg/dL were as follows: constant terms, 12.193, 0.741, and -7.157; coefficients of LDL-C, -3.999, -4.409, and -5.145; coefficients of HDL-C, -3.869, -4.555, and -5.215; and coefficients of TC, 3.984, 4.547, and 5.231, respectively. The adjusted coefficients of determination were 0.547, 0.593, and 0.678, respectively (P < 0.001, P < 0.001, and P < 0.001, respectively). Conclusion: Fasting TG levels can be calculated from TC, LDL-C, and HDL-C levels when nHDL-C levels are <160 mg/dL. Using nonfasting TG and eTG levels as indicators of hypertriglyceridemia might eliminate the need for venous sampling after overnight fasting.
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Affiliation(s)
- Masahito Katahira
- Aichi Prefectural University School of Nursing and Health, Nagoya, Japan
- Checkup Center, Daiyukai Daiichi Hospital, Ichinomiya, Japan
| | - Shu Imai
- Checkup Center, Daiyukai Daiichi Hospital, Ichinomiya, Japan
| | - Satoko Ono
- Checkup Center, Daiyukai Daiichi Hospital, Ichinomiya, Japan
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Katahira M, Tsunekawa T, Mizoguchi A, Yamaguchi M, Tsuru K, Takashima H, Terada R. Clinical significance of thyroglobulin antibodies and thyroid peroxidase antibodies in Graves' disease: a cross-sectional study. Hormones (Athens) 2023; 22:253-261. [PMID: 36811756 DOI: 10.1007/s42000-023-00437-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 02/07/2023] [Indexed: 02/24/2023]
Abstract
PURPOSE The significance of thyroglobulin antibodies (TgAbs) and thyroid peroxidase antibodies (TPOAbs) in Graves' disease (GD) remains unclear. Therefore, this study aimed to clarify the clinical significance of TgAbs and TPOAbs in GD. METHODS A total of 442 patients with GD were recruited and divided into four groups based on TgAb and TPOAb positivity. Their clinical parameters and the characteristics of the groups were compared. Cox proportional hazard regression analysis was performed to assess risk factors for GD remission. RESULTS The free triiodothyronine (FT3) level was significantly higher in groups positive for TgAbs and TPOAbs than in the other groups. The FT3 to free thyroxine (FT4) (FT3/FT4) ratio was significantly higher and thyrotropin-stimulating hormone (TSH) receptor antibodies (TRAbs) were significantly lower in the TgAb+/TPOAb- group. Time to FT4 recovery was significantly shorter for groups negative for TPOAbs, whereas time to TSH recovery was significantly longer for groups positive for TPOAbs. Cox proportional hazard regression analysis revealed that TgAb positivity, prolonged treatment duration with antithyroid drugs, and Graves' ophthalmopathy treated with methylprednisolone were significantly associated with GD remission and that a smoking history, elevated FT3/FT4 ratio, and treatment with propylthiouracil hindered GD remission. CONCLUSION The contributions of TgAbs and TPOAbs to GD pathogenesis differ. Patients positive for TgAbs develop GD with lower TRAb titers and undergo earlier remission than those negative for TgAbs. Patients positive for TPOAbs develop GD with high TRAb titers and need a long time to achieve remission.
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Affiliation(s)
- Masahito Katahira
- Aichi Prefectural University School of Nursing and Health, Togoku, Kamishidami, Moriyama-ku, Nagoya, 463-8502, Japan.
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, 2-2-22 Bunkyo, Ichinomiya, 491-8558, Japan.
| | - Taku Tsunekawa
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, 2-2-22 Bunkyo, Ichinomiya, 491-8558, Japan
| | - Akira Mizoguchi
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, 2-2-22 Bunkyo, Ichinomiya, 491-8558, Japan
| | - Mariko Yamaguchi
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, 2-2-22 Bunkyo, Ichinomiya, 491-8558, Japan
| | - Kahori Tsuru
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, 2-2-22 Bunkyo, Ichinomiya, 491-8558, Japan
| | - Hiromi Takashima
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, 2-2-22 Bunkyo, Ichinomiya, 491-8558, Japan
| | - Ryoma Terada
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, 2-2-22 Bunkyo, Ichinomiya, 491-8558, Japan
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Katahira M, Moriura S, Ono S. Estimation of visceral fat area using criteria for metabolic syndrome: A cross-sectional study. Diabetes Metab Syndr 2022; 16:102584. [PMID: 35933939 DOI: 10.1016/j.dsx.2022.102584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 07/19/2022] [Accepted: 07/21/2022] [Indexed: 11/18/2022]
Abstract
BACKGROUND AND AIMS The aim of this study was to calculate the visceral fat area (VFA) based on the criteria for metabolic syndrome (MetS). METHODS A multiple regression analysis was performed to determine the estimated VFA using data from Japanese participants (2315 men and 1684 women). Receiver operating characteristic curve (ROC) analyses were performed to determine the optimal estimated VFA cutoff for the diagnosis of central obesity. The cutoff was also applied to a second cohort to validate the model. RESULTS The estimated VFA was calculated using the MetS criteria, age, and body mass index (adjusted coefficient of determination = 0.682 for men and 0.726 for women). The area under the ROC curve for waist circumference, VFA, and estimated VFA were 0.669, 0.741, and 0.749, respectively, for men and 0.711, 0.787, and 0.803, respectively, for women. The optimal cutoffs for estimated VFA were 128.1 cm2 for men and 82.2 cm2 for women. Multivariate logistic regression for heart disease revealed that estimated VFA, rather than waist circumference, was associated with a high risk of heart disease. CONCLUSION The estimated VFA is a better index of central obesity than waist circumference and VFA for the diagnosis of MetS.
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Affiliation(s)
- Masahito Katahira
- Aichi Prefectural University School of Nursing and Health, Togoku, Kamishidami, Moriyama-ku, Nagoya, 463-8502, Japan; Checkup Center, Daiyukai Daiichi Hospital, 1-6-12 Hagoromo, Ichinomiya, 491-8551, Japan.
| | - Shigeaki Moriura
- Checkup Center, Daiyukai Daiichi Hospital, 1-6-12 Hagoromo, Ichinomiya, 491-8551, Japan
| | - Satoko Ono
- Checkup Center, Daiyukai Daiichi Hospital, 1-6-12 Hagoromo, Ichinomiya, 491-8551, Japan
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Katahira M, Ogata H, Takashima H, Ito T, Hodai Y, Miwata T, Goto M, Yamaguchi M, Mizoguchi A, Kawakubo M, Nakamura S. Critical amino acid variants in HLA-DRB1 allotypes in the development of Graves' disease and Hashimoto's thyroiditis in the Japanese population. Hum Immunol 2020; 82:226-231. [PMID: 33386169 DOI: 10.1016/j.humimm.2020.12.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/27/2020] [Accepted: 12/11/2020] [Indexed: 11/17/2022]
Abstract
The effects of amino acid variants encoded by human leukocyte antigen (HLA) class II on the development of Graves' disease (GD) and Hashimoto's thyroiditis (HT) have not been fully elucidated. We investigated the HLA-DRB1 genes of 243 GD patients and 82 HT patients in the Japanese population and compared the frequencies of HLA-DRB1 alleles and HLA-DRB1 amino acid variants between these patients and the Japanese populations previously reported by another institution. The frequencies of HLA-DRB1*04:05 and -DRB1*14:03 alleles were significantly higher and those of HLA-DRB1*01:01 and -DRB1*15:02 alleles were lower in GD patients than in controls. The frequencies of HLA-DRB1*08:03 and -DRB1*09:01 alleles were significantly higher and that of the HLA-DRB1*13:02 allele was lower in HT patients than in controls. A blind association analysis with all amino acid positions identified DRß9 and DRß31 for GD and DRß9, DRß13, and DRß21 for HT. The frequency of Glu-9 was significantly higher and that of Cys-9 was lower in GD patients than in controls. The frequencies of Lys-9 and Phe-13 were significantly higher in HT patients than in controls. DRß9 and DRß13 could be critical amino acid positions in the development of GD and HT.
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Affiliation(s)
- Masahito Katahira
- Aichi Prefectural University School of Nursing and Health, Nagoya, Japan; Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan.
| | - Hidetada Ogata
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - Hiromi Takashima
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - Takahiro Ito
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - Yuichi Hodai
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan; Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Tsutomu Miwata
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan; Department of Endocrinology and Diabetes, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Megumi Goto
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - Mariko Yamaguchi
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - Akira Mizoguchi
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan
| | - Mitsuhiro Kawakubo
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan; Department of Internal Medicine, Nishio Municipal Hospital, Nishio, Japan
| | - Shizuka Nakamura
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan
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Hayasaka K, Shiono S, Matsumura Y, Suzuki H, Yanagawa N, Abe J, Sagawa M, Sakurada A, Katahira M, Takahashi S, Endoh M, Okada Y. P3.16-03 Uncommon EGFR Mutations as a Worse Prognostic Factor for Surgically Resected Lung Adenocarcinoma. J Thorac Oncol 2018. [DOI: 10.1016/j.jtho.2018.08.1910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Katahira M, Ogata H, Ito T, Miwata T, Goto M, Nakamura S, Takashima H. Association of Autoimmune Thyroid Disease with Anti-GAD Antibody ELISA Test Positivity and Risk for Insulin Deficiency in Slowly Progressive Type 1 Diabetes. J Diabetes Res 2018; 2018:1847430. [PMID: 30116734 PMCID: PMC6079579 DOI: 10.1155/2018/1847430] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/23/2018] [Accepted: 05/28/2018] [Indexed: 12/28/2022] Open
Abstract
The presence of antiglutamic acid decarboxylase antibody (GADA) is required for the diagnosis of slowly progressive type 1 diabetes (SPT1D). We examined the factors influencing GADA determination by radioimmunoassay (GADA-RIA) and by enzyme-linked immunosorbent assay (GADA-ELISA). Sixty patients with SPT1D and 154 patients with type 2 diabetes were examined by both GADA-RIA and GADA-ELISA and for the presence of autoimmune thyroid disease (AITD). We compared the clinical characteristics of these patients based on the positivity or negativity of GADA-RIA and GADA-ELISA, and the existence or nonexistence of AITD. Thirty of 60 (50.0%) GADA-RIA-positive patients were GADA-ELISA negative, whereas none of the 154 GADA-RIA-negative patients were GADA-ELISA positive. Concomitant AITD was significantly less in patients with GADA-RIA and without GADA-ELISA and was significantly more in patients with GADA-RIA and GADA-ELISA. In GADA-RIA-positive patients, there was no significant difference in the GADA-RIA titer among the GADA-ELISA-negative patients with and without AITD, and the GADA-ELISA-positive patients without AITD; whereas the frequency of insulin deficiency was significantly higher in the patients with AITD and/or GADA-ELISA than in those without AITD and GADA-ELISA. Examination of GADA-ELISA and AITD in GADA-RIA-positive patients might be useful in predicting insulin deficiency in these patients.
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Affiliation(s)
- Masahito Katahira
- Aichi Prefectural University School of Nursing and Health, Nagoya 463-8502, Japan
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya 491-8558, Japan
| | - Hidetada Ogata
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya 491-8558, Japan
| | - Takahiro Ito
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya 491-8558, Japan
| | - Tsutomu Miwata
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya 491-8558, Japan
| | - Megumi Goto
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya 491-8558, Japan
| | - Shizuka Nakamura
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya 491-8558, Japan
- Department of General Internal Medicine, Matsunami General Hospital, Gifu 501-6062, Japan
| | - Hiromi Takashima
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya 491-8558, Japan
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Abstract
Objective The recurrence rate associated with antithyroid drug (ATD) treatment for Graves' disease (GD) is high compared with that for radioiodine therapy or surgery. It is important to identify patients in whom remission is unlikely, so that they are not given treatment that is destined to fail. The objective of this study was thus to evaluate factors influencing the prognosis of GD patients treated with ATDs. Patients One hundred and sixty-one patients were divided into two groups: 100 patients who could not discontinue ATDs for eight years or more (refractory group) and 61 patients who achieved remission within eight years after starting ATD treatment (nonrefractory group). The groups were compared in terms of age, thyroid function and thyroid-related autoantibodies at diagnosis, and the durations to the recovery of thyroid function and thyroid-related autoantibodies. Results The baseline levels of free triiodothyronine (T3), free thyroxine (T4), thyroid-stimulating antibodies (TSAbs) and thyroid-stimulating hormone (TSH) receptor antibodies (TRAbs) were high, and the age at diagnosis and the baseline level of thyroglobulin autoantibodies (TgAbs) were low in the refractory group compared with those in the nonrefractory group. The durations to the recovery of TSH, free T4, TRAb and TSAb levels were longer in the refractory group than in the nonrefractory group. No significant difference was observed with regard to thyroid peroxidase autoantibodies. Conclusion We compared the clinical features of these two groups in order to identify factors influencing the prognosis of GD patients treated with ATDs. A low baseline level of TgAbs is associated with the refractoriness of GD to ATD treatment.
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Shiono S, Katahira M, Abiko M, Yanagawa N. P-248THE RISK FACTOR OF LOCAL RECURRENCE AT THE SURGICAL MARGIN IN PULMONARY WEDGE RESECTION. Interact Cardiovasc Thorac Surg 2015. [DOI: 10.1093/icvts/ivv204.248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Katahira M, Hanakita M, Ito T, Suzuki M. The ratio of glycosylated albumin to glycosylated hemoglobin differs between type 2 diabetic patients with low normoalbuminuria and those with high normoalbuminuria or microalbuminuria. Diabetes Care 2013; 36:e207-8. [PMID: 24265377 PMCID: PMC3836087 DOI: 10.2337/dc13-1243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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Katahira M, Hanakita M, Ito T, Suzuki M, Segawa S. The age of onset of diabetes and glutamic acid decarboxylase titer measured long after diagnosis are associated with the clinical stage of slow-onset type 1 diabetes. Diabetes Res Clin Pract 2013; 99:93-7. [PMID: 23273838 DOI: 10.1016/j.diabres.2012.11.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2012] [Revised: 11/08/2012] [Accepted: 11/23/2012] [Indexed: 10/27/2022]
Abstract
AIMS Diabetes mellitus is divided into 3 clinical stages: not insulin requiring, insulin requiring for control, and insulin requiring for survival. We investigated the clinical characteristics of patients with slow-onset type 1 diabetes (T1D) to examine which clinical factors influence the clinical stage. METHODS One hundred fifty patients with slow-onset T1D were divided into 3 groups based on disease stage, and clinical features were compared among these groups. The patients were also divided into 4 groups based on the age of onset and the glutamic acid decarboxylase antibody (GAD-Ab) titer, which was measured long after diagnosis (mean, 9.2 years). The frequencies of the 3 stages were compared among these 4 groups. RESULTS The age of onset and the log (GAD-Ab) titer differed significantly among the 3 stages. The number of patients not requiring insulin was significantly higher and the number of those requiring insulin for survival was significantly lower in the group in which the age of onset was ≥50 and the log (GAD-Ab) titer <0.6, while the opposite pattern was observed in the group in which the age of onset was <50 and the log(GAD-Ab) titer ≥0.6. CONCLUSIONS Our results suggest that the combination of the age of onset and GAD-Ab titer measured long after diagnosis might predict the clinical stage of slow-onset T1D.
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Affiliation(s)
- Masahito Katahira
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya 491-8558, Japan.
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Katahira M, Hanakita M, Yasuda Y, Maeda H, Ito T, Segawa S. Effect of human leukocyte antigen class II genes on insulin deficiency in slow-onset type 1 diabetes in the Japanese population. Diabetes Res Clin Pract 2011; 93:e33-6. [PMID: 21497933 DOI: 10.1016/j.diabres.2011.03.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Revised: 02/28/2011] [Accepted: 03/21/2011] [Indexed: 10/18/2022]
Abstract
The aim of this study is to determine the contribution of human leukocyte antigen (HLA) class II genes to insulin deficiency in slow-onset type 1 diabetes (T1D). Our results suggest that the susceptibility conferred by HLA subtypes to slow-onset T1D differs between insulin-deficient patients and non-insulin-deficient patients.
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Affiliation(s)
- Masahito Katahira
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, 2-2-22 Bunkyo, Ichinomiya, Aichi 491-8558, Japan.
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Katahira M, Segawa S, Maeda H, Yasuda Y. Effect of human leukocyte antigen class II genes on acute-onset and slow-onset type 1 diabetes in the Japanese population. Hum Immunol 2010; 71:789-94. [PMID: 20510319 DOI: 10.1016/j.humimm.2010.05.020] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Revised: 05/13/2010] [Accepted: 05/19/2010] [Indexed: 10/19/2022]
Abstract
The contribution of the human leukocyte antigen (HLA) subtype to slow-onset type 1 diabetes (T1D), which includes latent autoimmune diabetes in adults (LADA), remains unclear in the Japanese population. We compared the frequencies of HLA DR-DQ haplotypes and genotypes of 72 acute-onset T1D patients, 100 slow-onset T1D patients, and 292 control subjects. The frequencies of DRB1*0405-DQB1*0401 (DR4) and DRB1*1302-DQB1*0604 (DR13) haplotypes were significantly higher in acute-onset patients, whereas that of the DRB1*1502-DQB1*0601 haplotype was significantly lower than those in slow-onset diabetes patients and controls. In contrast, DRB1*0802-DQB1*0302 (DR8) and DRB1*0901-DQB1*0303 (DR9) haplotypes were significantly more frequent, and the DRB1*1501-DQB1*0602 haplotype was extremely rare, in acute-onset patients and slow-onset diabetes patients. Genotype analysis revealed that DR4/9, DR4/13, and DR9/13 in acute-onset patients indicated high odds ratios (6.81, 12.0, and 15.6, respectively), whereas DR4/8 was significantly more frequent in slow-onset diabetes patients, but not in acute-onset patients. Our study demonstrated for the first time that the DR8 haplotype confers susceptibility to slow-onset T1D in the Japanese population. Moreover, there potentially are hierarchies for predisposing haplotypes, namely, DR13 > DR4 > DR9 > DR8 and for protective haplotypes, namely, DRB1*1501-DQB1*0602 > DRB1*1502-DQB1*0601.
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Affiliation(s)
- Masahito Katahira
- Department of Endocrinology and Diabetes, Ichinomiya Municipal Hospital, Ichinomiya, Japan.
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Katahira M, Maeda H, Tosaki T, Segawa S. The human leukocyte antigen class II gene has different contributions to autoimmune type 1 diabetes with or without autoimmune thyroid disease in the Japanese population. Diabetes Res Clin Pract 2009; 85:293-7. [PMID: 19581015 DOI: 10.1016/j.diabres.2009.06.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Revised: 05/28/2009] [Accepted: 06/08/2009] [Indexed: 11/25/2022]
Abstract
AIM Type 1 diabetes (T1D) is associated with autoimmune thyroid disease (AITD). The human leukocyte antigen (HLA) has been extensively studied in these diseases. We aimed to clarify the contribution of AITD on the susceptibility and resistance of the HLA subtype to autoimmune T1D in the Japanese population. METHODS The frequency of the HLA DR-DQ haplotype was compared between 56 autoimmune T1D patients with AITD and 71 autoimmune T1D patients without AITD, and control subjects. RESULTS The frequencies of DRB1 0405-DQB1 0401, DRB1 0802-DQB1 0302, and DRB1 0901-DQB1 0303 haplotypes were significantly higher in T1D patients with AITD than in control subjects. The frequencies of DRB1 0101-DQB1 0501, DRB1 0901-DQB1 0303, and DRB1 1302-DQB1 0604 haplotypes were significantly higher in T1D patients without AITD than in control subjects. The frequencies of DRB1 1101-DQB1 0301 and DRB1 1501-DQB1 0602 haplotypes were significantly lower in T1D patients with or without AITD than in control subjects. CONCLUSIONS Our results suggest that the susceptibility of the HLA subtype to autoimmune T1D differs between T1D with AITD and T1D without AITD, whereas there is no difference between the two groups with regard to HLA subtypes that confer protection against autoimmune T1D.
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Affiliation(s)
- Masahito Katahira
- Department of Endocrinology, Ichinomiya Municipal Hospital, 2-2-22 Bunkyo, Ichinomiya, Aichi 491-8558, Japan.
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Katahira M, Ishiguro T, Segawa S, Kuzuya-Nagao K, Hara I, Nishisaki T. Reevaluation of human leukocyte antigen DR-DQ haplotype and genotype in type 1 diabetes in the Japanese population. Horm Res 2008; 69:284-9. [PMID: 18259107 DOI: 10.1159/000114859] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Accepted: 06/06/2007] [Indexed: 01/20/2023]
Abstract
AIM This study aims at clarifying the human leukocyte antigen haplotypes and genotypes conferring susceptibility or resistance to type 1 diabetes in the Japanese population. METHODS The frequencies of human leukocyte antigen DR-DQ haplotypes and genotypes were compared between 83 type 1 diabetic patients, except for fulminant type 1 diabetes, and control subjects in the Japanese population. The patients were divided by onset age into four groups (ages 5-14, 15-29, 30-49, and 50-71 years); the haplotype frequency was compared between each group. RESULTS The frequencies of DRB1*0405-DQB1*0401 (DR4), DRB1*0802-DQB1*0302 (DR8), DRB1*0901-DQB1*0303 (DR9), and DRB1*1302-DQB1* 0604 (DR13) haplotypes were significantly higher in the patients than in the control subjects. The frequencies of DRB1* 1501-DQB1*0602 and DRB1*1502-DQB1*0601 haplotypes were significantly lower in the patients than in the controls. The frequencies of DR4/8, DR4/13, DR9/9, and DR9/13 genotypes were significantly higher in the patients than in the control subjects. The DR13 haplotype was the most frequent haplotype in the age group 30-49 years, whereas the other haplotypes but DR13 were the most frequent in the other age groups. CONCLUSION DR4, DR8, DR9, and DR13 haplotypes confer susceptibility to type 1 diabetes in Japanese patients.
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Affiliation(s)
- Masahito Katahira
- Department of Endocrinology, Ichinomiya Municipal Hospital, Ichinomiya, Japan.
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Abstract
A 48-year-old woman was referred to our hospital because of secondary hypothyroidism. Upon admission a left adrenal tumor was also detected using computed tomography. Laboratory data and adrenal scintigraphy were compatible with Cushing syndrome due to the left adrenocortical adenoma, although she showed no response to the TRH stimulation test. Hypercortisolism resulting in secondary hypothyroidism was diagnosed. After a left adrenalectomy, hydrocortisone administration was begun and the dose was reduced gradually. After discharge on the 23rd postoperative day, she began to suffer from anorexia. ACTH level remained low, and serum cortisol, free thyroxine and TSH levels were within the normal range. Since her condition became worse, she was re-admitted on the 107th postoperative day at which time serum calcium level was high (15.6 mg/dl). Both ACTH response to the CRH stimulation test and TSH response to the TRH stimulation test were restored to almost normal levels, but there was no response of cortisol to CRH stimulation test. We diagnosed that the hypercalcemia was due to adrenal insufficiency. Although the serum calcium level decreased to normal after hydrocortisone was increased (35 mg/day), secondary hypothyroidism recurred. It was suggested that sufficient glucocorticoids suppressed TSH secretion mainly at the pituitary level, which resulted in secondary (corticogenic) hypothyroidism. However, both postoperative glucocorticoid deficiency and adequate amounts of thyroxine due to the elimination of inhibition of TSH secretion by glucocorticoids might cause hypercalcemia possibly through increased bone reabsorption of calcium.
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Affiliation(s)
- Masahito Katahira
- Department of Internal Medicine, Kyoritsu General Hospital, Okazi, Japan
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17
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Tanaka Y, Hori T, Tagaya M, Katahira M, Nishikawa F, Sakamoto T, Kurihara Y, Nishikawa S, Uesugi S. NMR analysis of tertiary interactions in HDV ribozymes. Nucleic Acids Symp Ser 2003:285-6. [PMID: 12903380 DOI: 10.1093/nass/44.1.285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Three variants of minimized hepatitis delta virus (HDV) RNA ribozyme systems designed on the basis of the "pseudoknot" model were synthesized and their tertiary interactions were analyzed by NMR spectroscopy. Rz-1 is a cis-acting ribozyme system (the cleaved form, 56-mer) in which stem IV is deleted from the active domain of genomic HDV RNA. Rz-1 was uniformly labeled with stable isotopes, 13C and 15N. Rz-2 is a trans-acting ribozyme system (substrate: 8-mer, the cytidine residue at the cleavage site is replaced by 2'-O-methylcytidine; enzyme: 16-mer plus 35-mer). Rz-2 was partially labeled with stable isotopes in guanosine residues of enzyme 35mer. Rz-4 is a trans-acting ribozyme system (substrate: 8mer, the cytidine residue at the cleavage site is replaced by 2'-O-methylcytidine; enzyme 53mer) which was designed by Perrotta and Been. Rz-4 has the same sequence and an extra loop closing stem IV. From 2D-NOESY and 2D-HSQC (except for Rz-4) spectra, it was suggested each ribozyme forms "pseudoknot" type structure in solution. Additionally, it was found that G38 of Rz-1, G28 and G29 of Rz-2 and Rz-4 form base-pairs. These novel base-pairs are observed in the crystal structure of a modified genomic HDV RNA. From temperature change experiment of Rz-2, the imino proton signal of G28 disappeared at 50 degrees C earlier than the other corresponding signals. Upon MgCl2 titration of Rz-2, this signal showed the largest shift.
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Affiliation(s)
- Y Tanaka
- Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
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18
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Abstract
The structure of an RNA oligomer, r (GGAGGUUUUGGAGG) (R14-2) whose G-G steps are separated by adenine and uracil residues has been investigated by NMR. In the presence of 20 mM K+, a novel dimeric multiplex architecture is adopted by two strands of R14-2. In each strand a UUUU loop and two A residues connect four parallel G-G steps that pair-align into two tetrads. One of the tetrads is further pair-aligned by two A residues through the sheared mismatch and a novel hexad is subsequently formed. Two hexads coming from two different strands stack to make a dimeric multiplex. All of the guanosine and adenosine residues take an anti conformation.
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Affiliation(s)
- H Liu
- Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University
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19
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Matsugami A, Ouhashi K, Kanagawa M, Liu H, Kanagawa S, Uesugi S, Katahira M. New quadruplex structure of GGA triplet repeat DNA--an intramolecular quadruplex composed of a G:G:G:G tetrad and G(:A):G(:A):G(:A):G heptad, and its dimerization. Nucleic Acids Res Suppl 2003:271-2. [PMID: 12836369 DOI: 10.1093/nass/1.1.271] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The structure of d(GGAGGAGGAGGA) containing four tandem repeats of a GGA triplet sequence has been determined under physiological K+ conditions by NMR. d(GGAGGAGGAGGA) folds into an intramolecular quadruplex composed of a G:G:G:G tetrad and a G(:A):G(:A):G(:A):G heptad. Four G-G segments of d(GGAGGAGGAGGA) are aligned parallel to each other due to seven successive turns of the main chain at each of the GGA and GAGG segments. Two quadruplexes form a dimer stabilized through a stacking interaction between the heptads of the two quadruplexes. On the basis of these results, the biological implications of naturally occurring GGA triplet repeat DNA are discussed.
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Affiliation(s)
- A Matsugami
- Department of Environment and Natural Sciences, Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
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Abstract
A 20-year-old Japanese man was admitted to our hospital because of thirst and weight loss. His fasting plasma glucose, glycated hemoglobin, and urinary C-peptide were 262 mg/dl, 13.6%, and 44.8 microg/day, respectively, and the autoimmune antibodies related to type 1 diabetes were negative. Chromosome analysis of his peripheral blood lymphocytes showed a mos45,XY,der(14;14)(q10;ql0)[129]/ 46,XY,+14, der(14;14)(q10;q10)[1] karyotype. His parents were karyotypically normal. Microsatellite marker analysis on chromosome 14 demonstrated mosaic maternal segmental isodisomy for 14q21-q24. Although the parents had normal glucose regulation, the patient who finally returned to impaired glucose tolerance and his mother both have a deficiency in early postprandial insulin secretion. Since obesity was mild (body mass index, 24.1 kg/m2) and he was relatively young for type 2 diabetes, we speculated that his isodisomy 14 may have been involved in the onset of diabetes mellitus in this patient.
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21
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Kayashima T, Katahira M, Harada N, Miwa N, Ohta T, Yoshiura KI, Matsumoto N, Nakane Y, Nakamura Y, Kajii T, Niikawa N, Kishino T. Maternal isodisomy for 14q21-q24 in a man with diabetes mellitus. Am J Med Genet 2002; 111:38-42. [PMID: 12124731 DOI: 10.1002/ajmg.10511] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We report a 20-year-old man with maternal uniparental disomy for chromosome 14 (UPD14) and maturity-onset diabetes mellitus (DM). He had pre- and postnatal growth retardation, developed DM at age 20 years without any autoimmune antibodies, and had a mosaic 45,XY,der(14;14)(q10;q10)[129]/46,XY,+14,der(14;14)(q10;q10)[1] karyotype. Allelotyping using microsatellite markers covering the entire 14q indicated segmental maternal isodisomy for 14q21-q24 and maternal heterodisomy of the remaining regions of the chromosome. It is thus tempting to speculate that the segmental isodisomy led to reduction to homozygosity for a mutant gene and thus caused his DM, although the possibility of coincidental occurrence of the two events cannot totally be ruled out. Fluorescence in situ hybridization (FISH) analysis using BAC clone probes revealed that the isodisomic segment did not overlap any known IDDM or NIDDM susceptibility loci on chromosome 14, suggesting a novel locus for a subset of DM at the isodisomic segment.
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22
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Matsugami A, Ouhashi K, Kanagawa M, Liu H, Kanagawa S, Uesugi S, Katahira M. An intramolecular quadruplex of (GGA)(4) triplet repeat DNA with a G:G:G:G tetrad and a G(:A):G(:A):G(:A):G heptad, and its dimeric interaction. J Mol Biol 2001; 313:255-69. [PMID: 11800555 DOI: 10.1006/jmbi.2001.5047] [Citation(s) in RCA: 125] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The structure of d(GGAGGAGGAGGA) containing four tandem repeats of a GGA triplet sequence has been determined under physiological K(+) conditions. d(GGAGGAGGAGGA) folds into an intramolecular quadruplex composed of a G:G:G:G tetrad and a G(:A):G(:A):G(:A):G heptad. Four G-G segments of d(GGAGGAGGAGGA) are aligned parallel with each other due to six successive turns of the main chain at each of the GGA and GAGG segments. Two quadruplexes form a dimer stabilized through a stacking interaction between the heptads of the two quadruplexes. Comparison of the structure of d(GGAGGAGGAGGA) with the reported structure of d(GGAGGAN) (N=G or T) containing two tandem repeats of the GGA triplet revealed that although the two structures resemble each other to some extent, the extension of the repeats of the GGA triplet leads to distinct structural differences: intramolecular quadruplex for 12-mer versus intermolecular quadruplex for 7-mer; heptad versus hexad in the quadruplex; and three sheared G:A base-pairs versus two sheared G:A base-pairs plus one A:A base-pair per quadruplex. It was also suggested that d(GGAGGAGGAGGA) forms a similar quadruplex under low salt concentration conditions. This is in contrast to the case of d(GGAGGAN) (N=G or T), which forms a duplex under low salt concentration conditions. On the basis of these results, the structure of naturally occurring GGA triplet repeat DNA is discussed.
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Affiliation(s)
- A Matsugami
- Department of Environment and Natural Sciences, Graduate School of Environment and Information Sciences, Yokohama National University, 79-7 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan
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23
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Katahira M, Miyanoiri Y, Enokizono Y, Matsuda G, Nagata T, Ishikawa F, Uesugi S. Structure of the C-terminal RNA-binding domain of hnRNP D0 (AUF1), its interactions with RNA and DNA, and change in backbone dynamics upon complex formation with DNA. J Mol Biol 2001; 311:973-88. [PMID: 11531333 DOI: 10.1006/jmbi.2001.4862] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heterogeneous nuclear ribonucleoprotein (hnRNP) D0 has two ribonucleoprotein (RNP) -type RNA-binding domains (RBDs), each of which can specifically bind to the UUAG-sequence. hnRNP D0 also binds specifically to single-stranded d(TTAGGG)(n), the human telomeric DNA repeat. We have already reported the structure and interactions with RNA of the N-terminal RBD (RBD1). Here, the structure of the C-terminal RBD (RBD2) determined by NMR is presented. It folds into a compact alpha beta structure comprising an antiparallel beta-sheet packed against two alpha-helices, which is characteristic of RNP-type RBDs. In addition to the four beta-strands commonly found in RNP-type RBDs, an extra beta-strand, termed beta 4(-), was found just before the fourth beta-strand, yielding a five-stranded beta-sheet. Candidate residues of RBD2 involved in the interactions with RNA were identified by chemical shift perturbation analysis. Perturbation was detected on the beta-sheet side, not on the opposite alpha-helix side, as observed for RBD1. It is notable that the beta 4(-) to beta 4 region of RBD2 is involved in the interactions in contrast to the case of RBD1. The chemical shift perturbation analysis also showed that RBD2 interacts with DNA in essentially the same way as with RNA. Changes in the backbone dynamics upon complex formation with DNA were examined by means of model free analysis of relaxation data. In free RBD2, the beta 4(-) to beta 4 region exhibits slow conformational exchange on the milli- to microsecond time scale. The exchange is quenched upon complex formation. The flexibility of free RBD2 may be utilized in the recognition process by allowing different conformational states to be accessed and facilitating induced fit. Additionally, faster flexibility on the nano- to picosecond time scale was observed for loop 3 located between beta 2 and beta 3 in free RBD2, which is retained by the complex as well.
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Affiliation(s)
- M Katahira
- Department of Environment and Natural Sciences, Graduate School of Environment and Information Sciences, 79-7 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan
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24
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Katahira M. Relationship between anti-insulin antibodies and albuminuria or proteinuria in human insulin-treated type 2 diabetes mellitus. Endocr J 2001; 48:487-91. [PMID: 11603572 DOI: 10.1507/endocrj.48.487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In order to examine the relationship between anti-insulin antibodies (AIA) caused by extrinsic human insulin and albuminuria or proteinuria, 53 human insulin-treated type 2 diabetics were divided into two groups: (AIA(+) group) 27 patients with a titer of AIA greater than 7.6% and (AIA(-) group) 26 patients with a titer of AIA less than 7.5%. Although no significant difference was found between the two groups for age, gender, body mass index, duration of diabetes, duration of insulin treatment, blood pressure, serum creatinine, glycosylated hemoglobin (HbA1c), daily dose of insulin, daily insulin injection times, or treatment of hypertension, the AIA(+) group had a significantly higher urinary albumin to creatinine ratio and urinary protein to creatinine ratio than the AIA(-) group (p < 0.05). It is suggested that AIA in type 1 diabetics might be insulin autoantibodies, which is not the case with type 2 diabetics. To our knowledge this is the first study demonstrating the relationship between AIA induced not by porcine or bovine insulin, but by human insulin and albuminuria or proteinuria in type 2 diabetics.
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Affiliation(s)
- M Katahira
- Department of Internal Medicine, Okazaki City Hospital, Aichi, Japan
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25
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Yasuno K, Yamazaki T, Tanaka Y, Kodama TS, Matsugami A, Katahira M, Ishihama A, Kyogoku Y. Interaction of the C-terminal domain of the E. coli RNA polymerase alpha subunit with the UP element: recognizing the backbone structure in the minor groove surface. J Mol Biol 2001; 306:213-25. [PMID: 11237595 DOI: 10.1006/jmbi.2000.4369] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The C-terminal domain of the alpha-subunit of Escherichia coli RNA polymerase (alphaCTD) is responsible for transcriptional activation through interaction with both activator proteins and UP element DNA. Previously, we determined the solution structure of alphaCTD. Here, we investigated the interaction between alphaCTD and UP element DNA by NMR. DNA titration curves and intermolecular NOE measurements indicate that alphaCTD can bind to multiple sites on the UP element DNA. Unlike many transcription factors, alphaCTD does not have a strict base sequence requirement for binding. There is a good correlation between the strength of the interaction and the extent of intrinsic bending of the DNA oligomer estimated from the gel retardation assay. We propose that alphaCTD recognizes the backbone structure of DNA oligomers responsible for the intrinsic bending. Moreover, NMR studies and drug competition experiments indicated that alphaCTD interacts with the UP element on the minor groove side of the DNA. The C-terminal end of helix-1, the N-terminal end of helix-4, and the loop between helices 3 and 4 are used for the interaction. Based on these observations, we propose a model for the UP element-alphaCTD complex.
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Affiliation(s)
- K Yasuno
- Division of Molecular Biophysics, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Osaka, Suita, 565-0871, Japan
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26
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Katahira M, Kobayashi S, Matsugami A, Ouhashi K, Uesugi S, Yamamoto R, Taira K, Nishikawa S, Kumar P. Structural study of an RNA aptamer for a Tat protein complexed with ligands. Nucleic Acids Symp Ser 2000:269-70. [PMID: 10780483 DOI: 10.1093/nass/42.1.269] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
An RNA aptamer for an HIV Tat protein has been isolated by the in vitro SELEX method. The RNA aptamer binds to the Tat protein 50-100 times more strongly than native TAR RNA does. Here, we have investigated the structure of the RNA aptamer complexed with ligands, partial peptide fragments of the Tat protein or argininamide, by multidimensional 1H/13C/15N NMR. It is strongly suggested that two U:A:U base triples are formed in the RNA aptamer upon binding of ligands. Specific hydrogen bonds between arginine side chains of ligands and guanine bases located adjacent to the base triples are identified. On the basis of many intramolecular and intermolecular NOEs, a structural model of the complex has been constructed.
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Affiliation(s)
- M Katahira
- Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University, Japan
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27
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Tanaka Y, Hori T, Katahira M, Nishikawa F, Sakamoto T, Fukunaga Y, Kurihara Y, Nishikawa S, Uesugi S. Design and NMR analysis of HDV ribozymes for structural investigation. Nucleic Acids Symp Ser 2000:221-2. [PMID: 10780459 DOI: 10.1093/nass/42.1.221] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Three variants of minimized hepatitis delta virus (HDV) RNA ribozyme systems (Rz-1 to approximately Rz-3) (Fig. 1) were designed on the basis of the "pseudoknot" structure model and synthesized. Rz-1 is a cis-acting ribozyme system (a cleaved form, 56-mer) in which stem IV is deleted from the active domain of genomic HDV RNA. Rz-1 was uniformly labeled with stable isotopes, 13C and 15N. The 2D-NOESY and 2D-HSQC data for Rz-1 suggest that Rz-1 forms the pseudoknot structure and G38 which is opposite to the cleavage site makes a base-pair. Rz-2 is a trans-acting ribozyme system which consists of three RNA oligomer strands (substrate: 8-mer, the cytidine residue at the cleavage site is replaced by 2'-O-methylcytidine; enzyme: 16-mer plus 35-mer). Rz-3 is a ribozyme in which the three RNA strands of Rz-2 are connected. It turns out that Rz-3 forms an inactive structure with low cleavage activity (k(obs) = 0.009) and final cleavage yield (6%). Rz-3 has the highest cleavage activity at pH 5.5. The optimal activity at acidic pH is similar to that of the wild type ribozyme. We also synthesized and examined the activity and structure of Rz-4 (designed by Perrotta and Been) which consists of two RNA strands (1).
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Affiliation(s)
- Y Tanaka
- Faculty of Engineering, Yokohama National University, Japan
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28
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Yamamoto R, Katahira M, Nishikawa S, Baba T, Taira K, Kumar PK. A novel RNA motif that binds efficiently and specifically to the Ttat protein of HIV and inhibits the trans-activation by Tat of transcription in vitro and in vivo. Genes Cells 2000; 5:371-88. [PMID: 10886365 DOI: 10.1046/j.1365-2443.2000.00330.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND To find a novel RNA that would bind efficiently and specifically to Tat protein but not to other cellular factors, we used an in vitro selection method and isolated a novel aptamer RNATat, a 37-mer RNA oligomer, that binds efficiently to the Tat protein of HIV-1. In the present study, we analysed various properties of aptamer RNATat, including binding kinetics, identification of functional groups for Tat binding, and inhibition of Tat function. RESULTS The binding affinity of the isolated aptamer RNATat to Tat-1 was 133 times higher than that of authentic TAR-1 RNA. RNATat is composed of inverted repeats of two TAR-like motifs, and even though RNATat had two Tat-binding core elements, the interaction with Tat took place at a molar ratio of 1 : 1. Several functional groups of aptamer RNATat responsible for Tat binding were identified. The selected aptamer RNATat competed effectively for binding to Tat even in the presence of a large excess of TAR-1 or TAR-2 RNA in vitro, and specifically prevented Tat-dependent trans-activation both in vitro and in vivo. CONCLUSIONS Our results indicate that a novel aptamer, RNATat, retained strong affinity for Tat even in the presence of a large excess of HIV TAR. RNATat binds efficiently to Tat proteins or peptides derived from either HIV-1 or HIV-2. Unlike TAR RNA, RNATat affinity does not depend upon cellular proteins such as cyclin T1, thus RNATat has the potential for use as a molecular recognition element in biosensors.
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Affiliation(s)
- R Yamamoto
- National Institute of Bioscience and Human Technology, University of Tsukuba, Japan
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29
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Katahira M, Fukuda H, Kawasumi H, Sugimura T, Nakagama H, Nagao M. Intramolecular quadruplex formation of the G-rich strand of the mouse hypervariable minisatellite Pc-1. Biochem Biophys Res Commun 1999; 264:327-33. [PMID: 10529363 DOI: 10.1006/bbrc.1999.1521] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The minisatellite Pc-1, isolated from the mouse genome consisting of a tandem repeat of d(GGCAG), is hypervariable with a mutation rate of 0.15/generation. Here we describe a structural characterization of the G-rich strand of Pc-1 by biochemical and physicochemical methods. It was found to be comparatively resistant to both single-stranded DNA-binding protein binding and digestion by single-stranded DNA-specific nuclease and to cause arrest of DNA synthesis. The guanine imino proton NMR signals observed on the Pc-1 G-rich strand and their slow (1)H/(2)H exchange profiles pointed to a quadruplex structure with guanine quartets. The melting temperature of the quadruplex determined by CD was not dependent on DNA concentration. These results indicate that the G-rich strand of Pc-1 forms an intramolecular folded-back quadruplex structure under physiological conditions. Possible mechanisms of the Pc-1 mutations implicated with the formation of the quadruplex structure are discussed.
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Affiliation(s)
- M Katahira
- Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, 240, Japan
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30
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Nagata T, Kanno R, Kurihara Y, Uesugi S, Imai T, Sakakibara S, Okano H, Katahira M. Structure, backbone dynamics and interactions with RNA of the C-terminal RNA-binding domain of a mouse neural RNA-binding protein, Musashi1. J Mol Biol 1999; 287:315-30. [PMID: 10080895 DOI: 10.1006/jmbi.1999.2596] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Musashi1 is an RNA-binding protein abundantly expressed in the developing mouse central nervous system. Its restricted expression in neural precursor cells suggests that it is involved in the regulation of asymmetric cell division. Musashi1 contains two ribonucleoprotein (RNP)-type RNA-binding domains (RBDs), RBD1 and RBD2. Our previous studies showed that RBD1 alone binds to RNA, while the binding of RBD2 is not detected under the same conditions. Joining of RBD2 to RBD1, however, increases the affinity to greater than that of RBD1 alone, indicating that RBD2 contributes to RNA-binding. We have determined the three-dimensional solution structure of the C-terminal RBD (RBD2) of Musashi1 by NMR. It folds into a compact alpha beta structure comprising a four-stranded antiparallel beta-sheet packed against two alpha-helices, which is characteristic of RNP-type RBDs. Special structural features of RBD2 include a beta-bulge in beta2 and a shallow twist of the beta-sheet. The smaller 1H-15N nuclear Overhauser enhancement values for the residues of loop 3 between beta2 and beta3 suggest that this loop is flexible in the time-scale of nano- to picosecond order. The smaller 15N T2 values for the residues around the border between alpha2 and the following loop (loop 5) suggest this region undergoes conformational exchange in the milli- to microsecond time-scale. Chemical shift perturbation analysis indicated that RBD2 binds to an RNA oligomer obtained by in vitro selection under the conditions for NMR measurements, and thus the nature of the weak RNA-binding of RBD2 was successfully characterized by NMR, which is otherwise difficult to assess. Mainly the residues of the surface composed of the four-stranded beta-sheet, loops and C-terminal region are involved in the interaction. The appearance of side-chain NH proton resonances of arginine residues of loop 3 and imino proton resonances of RNA bases upon complex formation suggests the formation of intermolecular hydrogen bonds. The structural arrangement of the rings of the conserved aromatic residues of beta2 and beta3 is suitable for stacking interaction with RNA bases, known to be one of the major protein-RNA interactions, but a survey of the perturbation data suggested that the stacking interaction is not ideally achieved in the complex, which may be related to the weaker RNA-binding of RBD2.
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Affiliation(s)
- T Nagata
- Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan
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31
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Nagata T, Kurihara Y, Matsuda G, Saeki J, Kohno T, Yanagida Y, Ishikawa F, Uesugi S, Katahira M. Structure and interactions with RNA of the N-terminal UUAG-specific RNA-binding domain of hnRNP D0. J Mol Biol 1999; 287:221-37. [PMID: 10080887 DOI: 10.1006/jmbi.1999.2616] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heterogeneous nuclear ribonucleoprotein (hnRNP) D0 has two ribonucleoprotein (RNP)-type RNA-binding domains (RBDs), each of which can bind solely to the UUAG sequence specifically. The structure of the N-terminal RBD (RBD1) determined by NMR is presented here. It folds into a compact alphabeta structure comprising a four-stranded antiparallel beta-sheet packed against two alpha-helices, which is characteristic of the RNP-type RBDs. Special structural features of RBD1 include N-capping boxes for both alpha-helices, a beta-bulge in the second beta-strand, and an additional short antiparallel beta-sheet coupled with a beta-turn-like structure in a loop. Two hydrogen bonds which restrict the positions of loops were identified. Backbone resonance assignments for RBD1 complexed with r(UUAGGG) revealed that the overall folding is maintained in the complex. The candidate residues involved in the interactions with RNA were identified by chemical shift perturbation analysis. They are located in the central and peripheral regions of the RNA-binding surface composed of the four-stranded beta-sheet, loops, and the C-terminal region. It is suggested that non-specific interactions with RNA are performed by the residues in the central region of the RNA-binding surface, while specific interactions are performed by those in the peripheral regions. It was also found that RBD1 has the ability to inhibit the formation of the quadruplex structure.
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Affiliation(s)
- T Nagata
- Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan
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32
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Katahira M. [RNA recognition by RNA-binding protein]. Tanpakushitsu Kakusan Koso 1999; 44:506-17. [PMID: 10204003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- M Katahira
- Department of Chemistry and Biotechnology, Faculty of Engineering, Yokohama National University, Japan
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Katahira M, Kim MH, Sugiyama T, Nishimura Y, Uesugi S. Two metal-binding sites in a lead ribozyme bound to competitively by Pb2+ and Mg2+--induced structural changes as revealed by NMR. Eur J Biochem 1998; 255:727-33. [PMID: 9738914 DOI: 10.1046/j.1432-1327.1998.2550727.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We reported recently that a lead ribozyme with modified bases cleaved at an additional site at high Pb2+ concentrations (>0.1 mM), and that the cleavage at a canonical site was enhanced nearly fourfold at the optimum combination of Pb2+ and Mg2+ concentrations [Kim, M. H., Katahira, M., Sugiyama, T. & Uesugi, S. (1997) J. Biochem. (Tokyo) 122, 1062-1067]. Here we have identified two metal-binding sites (sites 1 and 2) of the lead ribozyme at the residue level by NMR. Both sites are located in an asymmetric internal loop of the lead ribozyme. Site 1 is composed of residues of an enzyme strand and site 2 of residues of a substrate strand. The two sites are bound to competitively by Pb2+ and Mg2+. It was revealed that at certain Pb2+ and Mg2+ concentrations, site 1 is occupied by Pb2+ and site 2 is occupied by Mg2+. The dependency of the cleavage at the canonical and other sites on the Pb2+ and Mg2+ concentrations is interpreted by considering the species of metal ions bound to the two sites. It is suggested that the addition of the two metal ions produces similar and different effects on the structure of the lead ribozyme, and the two metal ions have a synergistic effect on the structure.
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Affiliation(s)
- M Katahira
- Department of Bioengineering, Faculty of Engineering, Yokohama National University, Japan
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34
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Kobayashi S, Kamisato R, Kanagawa M, Katahira M, Uesugi S. The structures of nucleic acids composed exclusively of non-standard base pairs. Nucleic Acids Symp Ser 1998:103-4. [PMID: 9586020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We have reported that d(GGAGGAA) forms a new type of quadruplex in the presence of K+. Here we report that in the absence of K+ it forms another kind of new structure composed of non-standard base pairs exclusively. The structure is neither a quadruplex nor a hairpin. The structure gives three clear imino proton signals of G at 10.0, 13.0 and 13.8 ppm, indicating the formation of G:A and/or G:G base pairs. The two signals at 13.0 and 13.8 ppm indicate that there are two base pairs in which the imino protons of G are hydrogen bonded. All residues take anti conformation, which imposes the restriction on the combination of a mutual direction of strands and types of base pairs. Phosphorus signals of the second and fifth residues appear at higher field, while that of the seventh residue at lower field, when compared with those of A and B form structures, suggesting deviations of a backbone conformation from the standard one. Replacement of the second or fifth G by I results in destabilization of the structure, which implies the involvement of amino groups of these residues in base pairing. On the basis of these results, the structure of d(GGAGGAA) is discussed.
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Affiliation(s)
- S Kobayashi
- Department of Bioengineering, Faculty of Engineering, Yokohama National University, Japan
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35
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Tanaka Y, Sakamoto T, Sasa K, Kuwabara T, Kim MH, Kurihara Y, Katahira M, Uesugi S. Structure-activity correlation for an HDV ribozyme composed of three RNA strands. Nucleic Acids Symp Ser 1998:309-10. [PMID: 9586123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatitis delta virus (HDV) RNA ribozyme system which consists of three RNA oligomer strands (substrate 8-mer; enzyme 16-mer plus 35-mer, Fig. 1) was designed. Effects of Mg2+ concentration on the pseudo first-order rate constant (kobs) of RNA cleavage reaction and on conformation of ribozyme complex were examined. The secondary structure of the complex was also analyzed by limited digestion with ribonucleases. The kobs and CD data were analyzed by curve-fitting analysis using equations derived for two-Mg2+ and three-Mg2+ ion binding models. The result revealed that a three-Mg2+ binding model can explain the Mg(2+)-concentration-dependent changes of both conformation and activity of the HDV ribozyme.
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Affiliation(s)
- Y Tanaka
- Department of Bioengineering, Faculty of Engineering, Yokohama National University, Japan
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36
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Abstract
Although cytokines are known to be involved in the regulation of ACTH secretion, their effects, along with the molecular mechanisms, on POMC gene expression are not thoroughly characterized. In this study we examined the effects of representative cytokines on transcription of the POMC gene in corticotrophs in vitro using AtT20PL, a clone of the AtT20 cell line stably transfected with approximately 0.7 kilobase of the rat POMC 5'-promoter-luciferase fusion gene. In each experiment, cells were incubated with the cytokine tested, and the changes in POMC 5'-promoter activity were determined by a luciferase assay. The results showed that interleukin-1beta (IL-1beta) stimulated promoter activity in a biphasic manner [weak short term effects (2-3 h) followed by potent long term effects (>12-16 h)]. Tumor necrosis factor-alpha had similar effects, but much less potency. IL-6 showed a profound stimulatory, but only a long term (>20 h), effect. IL-2 did not influence POMC expression. In contrast, interferon-alpha (IFN alpha) and IFN-gamma showed acute stimulatory effects (approximately 4 h) followed by marked inhibitory effects (>8 h). Although the acute effects of IL-1beta, IL-6, and tumor necrosis factor-alpha alone were minimal, they significantly potentiated the stimulatory effect of CRH on POMC expression. Finally, pretreatment of the cells with a broad spectrum tyrosine kinase inhibitor, genistein, abolished or significantly diminished the effects of all cytokines except IFNs. Our results suggest that 1) each cytokine tested has a distinct effect on POMC gene expression; 2) there are positive cross-talk effects between CRH and cytokines at the corticotroph level; and 3) tyrosine phosphorylation cascades are involved in the intracellular signaling mechanisms of some cytokines.
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Affiliation(s)
- M Katahira
- First Department of Internal Medicine, Nagoya University School of Medicine, Japan
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37
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Kanagawa M, Okada Y, Uesugi S, Doi H, Katahira M. Structural characterization of a DNA duplex modeled on a DNA:RNA hybrid of the polypurine tract recognized by a reverse transcriptase. Nucleosides Nucleotides 1998; 17:831-41. [PMID: 9708337 DOI: 10.1080/07328319808004678] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The structure of d(TTAAAAGAAAAGGG):d(CCCTTTTCTTTTAA) has been characterized by NMR. The minor grooves of the two dA-tracts are suggested to be rather narrow, and the portion linking the two dA tracts exhibits a slightly deviated structure from a standard B DNA, in order to maintain the narrowness of the minor groove. The structure of the dG-tract is also slightly deviated. Additionally, specific broadening of resonances is observed for the residues at or near the junction between the dA-tract and the dG-tract, suggesting local structural polymorphology.
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Affiliation(s)
- M Kanagawa
- Department of Bioengineering, Faculty of Engineering, Yokohama National University, Japan
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38
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Katahira R, Katahira M, Yamashita Y, Ogawa H, Kyogoku Y, Yoshida M. Solution structure of the novel antitumor drug UCH9 complexed with d(TTGGCCAA)2 as determined by NMR. Nucleic Acids Res 1998; 26:744-55. [PMID: 9443966 PMCID: PMC147319 DOI: 10.1093/nar/26.3.744] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Aureolic acid group compounds, such as chromomycin A3(CHM) and mithramycin (MIT), are known as antitumor drugs. Recently we isolated a novel aureolic acid group antitumor drug, UCH9, from Streptomyces sp. The chemical structure of UCH9 is unique in that mono- (A ring) and tetrasaccharide (B-E rings) segments and a longer hydrophobic sidechain are attached to the chromophore, while di- and trisaccharide segments and a methyl group are attached to it in the cases of CHM and MIT. It has been shown by two-dimensional agarose gel electrophoresis that the three drugs cause DNA unwinding, UCH9 causing less than the others. A photo-CIDNP experiment has revealed that UCH9 binds to the minor groove of DNA. The structure of the UCH9-d(TTGGCCAA)2 complex has been determined by 1H NMR and simulated annealing calculations. The obtained structure indicates that UCH9 binds as a dimer to the minor groove of d(TTGGCCAA)2, like CHM and MIT, but that the structural change in DNA induced on binding of UCH9 is moderate in comparison with those on binding of the other two drugs. It turns out that the dimer structure of UCH9, stabilized presumably through a hydrophobic interaction involving the A, D and E rings and the hydrophobic sidechain is different from that of CHM and thus DNA can interact with UCH9 in the minor groove with a moderate structural change.
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Affiliation(s)
- R Katahira
- Tokyo Research Laboratories, Kyowa Hakko Kogyo Co. Ltd, 3-6-6 Asahimachi, Machida-shi, Tokyo 194, Japan
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39
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Abstract
The effect of Pb2+ and Mg2+ on the activity of a lead ribozyme with modified sequences has been studied. At low Pb2+ concentrations, cleavage at a previously reported site (site a) is observed. At higher Pb2+ concentrations, cleavage at a new site (site b) adjacent to site a is observed, while the cleavage at site a is repressed. On the addition of a certain amount of Mg2+, the cleavage at site a is enhanced by almost fourfold, while the cleavage at site b is repressed. Further addition of Mg2+ represses the cleavage at both sites. CD analysis indicates that the structure and stability of the lead ribozyme change depending on the metal conditions. Activation and repression of the activity by the combination of Pb2+ and Mg2+ are rationalized by considering that the two metals compete with each other for binding at two metal-binding sites.
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Affiliation(s)
- M H Kim
- Department of Bioengineering, Faculty of Engineering, Yokohama National University
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40
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Abstract
Max is a basic region/helix-loop-helix/leucine zipper (b/HLH/Z) protein that forms a hetero-complex with the Myc family proteins Myc, Mad, and Mxi1, and a homo-complex with itself. These complexes specifically bind to double-stranded DNA containing CACGTG sequences. Here, we report on the structural properties in aqueous solution of a 109-amino-acid protein, Max110, corresponding to the N-terminal domain of Max containing the b/HLH/Z motif (residues 2-110), as characterized by combined use of circular dichroism (CD) and sedimentation equilibrium experiments. The results showed that the alpha-helical content of Max110 increases with increasing protein concentration. The sedimentation equilibrium data indicated that Max110 exists as a monomer at low protein concentration, and forms a dimer at high protein concentration. Further increases in the alpha-helical content of Max110 occur upon addition of DNA with the CACGTG recognition sequence. Thus, dimerization and binding to DNA of Max both favor an increase of the alpha-helical content.
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Affiliation(s)
- M Horiuchi
- Department of Bioengineering, Faculty of Engineering, Yokohama National University
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41
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Sakamoto T, Kawai G, Katahira M, Kim MH, Tanaka Y, Kurihara Y, Kohno T, Watanabe S, Yokoyama S, Watanabe K, Uesugi S. Hairpin structure of an RNA 28-mer, which contains a sequence of the enzyme component of a hammerhead ribozyme system: evidence for tandem G:A pairs that are not of side-by-side type. J Biochem 1997; 122:556-62. [PMID: 9348084 DOI: 10.1093/oxfordjournals.jbchem.a021789] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
An RNA 28-mer (Rz28) was obtained as a major product by in vitro transcription with T7 RNA polymerase of a promoter-template DNA, which contains a sequence for the enzyme component, RNA 24-mer (Rz24), of a mutant hammerhead ribozyme system. Sequence analysis and enzymatic probing study showed that Rz28 has 4 extra nucleotides at the 3'-terminus, the sequence of which is complementary to that of the 5'-terminal sequence of Rz24, and forms a stable hairpin structure. NMR studies using a 15N-guanine-labeled derivative suggested that Rz28 contains tandem G:A pairs that are not of the side-by-side type which is found in the crystal structure of hammerhead ribozyme complexes. Comparison of the HMQC spectra of 15N-guanine-labeled Rz28 and Rz24 suggested that Rz24 also contains the same type of tandem G:A pairs.
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Affiliation(s)
- T Sakamoto
- Department of Bioengineering, Faculty of Engineering, Yokohama National University
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42
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Iwasaki Y, Aoki Y, Katahira M, Oiso Y, Saito H. Non-genomic mechanisms of glucocorticoid inhibition of adrenocorticotropin secretion: possible involvement of GTP-binding protein. Biochem Biophys Res Commun 1997; 235:295-9. [PMID: 9199185 DOI: 10.1006/bbrc.1997.6785] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We investigated non-genomic mechanisms of glucocorticoid negative feedback regulation on pituitary corticotroph cells using the AtT20 mouse corticotroph tumor cell line. A synthetic glucocorticoid dexamethasone (100 nM) potently suppressed forskolin-induced cAMP generation, adrenocorticotropin (ACTH) secretion, and proopiomelanocortin gene expression. When de novo gene expression was inhibited by actinomycin D (1 microM), dexamethasone still suppressed cAMP efflux and ACTH release, although less potently. Interestingly, under the same conditions, pretreatment of the cells with pertussis toxin (50 ng/ml) completely abolished the suppressive effect of dexamethasone on both parameters. These results suggest that non-genomic and genomic mechanisms are involved in the glucocorticoid negative regulation of ACTH expression, and a pertussis toxin-sensitive GTP-binding protein might, at least partly, participate in the non-genomic effect.
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Affiliation(s)
- Y Iwasaki
- First Department of Internal Medicine, Nagoya University School of Medicine, Showa-ku, Japan.
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43
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Sakamoto T, Tanaka Y, Kuwabara T, Kim MH, Kurihara Y, Katahira M, Uesugi S. Properties of hepatitis delta virus ribozyme, which consists of three RNA oligomer strands. J Biochem 1997; 121:1123-8. [PMID: 9354386 DOI: 10.1093/oxfordjournals.jbchem.a021704] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Properties of a hepatitis delta virus (HDV) RNA ribozyme system, which consists of three RNA oligomer strands (substrate 8-mer; enzyme 16-mer plus 35-mer) and contains a hybrid sequence of genomic and antigenomic RNA cores, are reported. Effects of Mg2+ concentration, divalent metal ion species, pH, and temperature on the cleavage activity were examined. The substrate cleavage activity increased with increasing Mg2+ concentration (0-100 mM). Ca2+ and Mn2+ ions were the most effective divalent cations and Mg2+ was less effective. The cleavage activity increased with increasing pH (5-7.5). The optimum temperature for the cleavage activity was 25-40 degrees C. The Mg2+ concentration, pH and temperature dependencies are different from those reported for the single-strand ribozymes (about 90-mer) although the divalent metal ion preference is very similar. Conformational change induced by Mg2+ ion titration was monitored by CD. The CD data and the activity-Mg2+ concentration data were analyzed by curve-fitting analysis using equations derived for multiple metal ion binding mechanisms. The data can be explained by a model in which three Mg2+ ions bind to one ribozyme unit.
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Affiliation(s)
- T Sakamoto
- Department of Bioengineering, Faculty of Engineering, Yokohama National University
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Aoki Y, Iwasaki Y, Katahira M, Oiso Y, Saito H. Regulation of the rat proopiomelanocortin gene expression in AtT-20 cells. I: Effects of the common secretagogues. Endocrinology 1997; 138:1923-9. [PMID: 9112388 DOI: 10.1210/endo.138.5.5121] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Although the effects of the various secretagogues on corticotropin (ACTH) secretion have been well studied, their effects on the POMC gene expression have not been thoroughly characterized. In this study, we established a new model system using the AtT20 mouse corticotroph tumor cell line transfected stably with a plasmid containing 0.7 kb of the rat POMC 5' promoter-luciferase fusion gene. The responsiveness to exogenous CRH improved markedly when the cells were cultured with low serum medium (1% FBS) compared with serum rich medium (10%). Using this culture condition, we examined the effects of not only CRH but also other secretagogues such as catecholamines, vasopressin, and angiotensin II, upon the transcriptional activity of the POMC gene. CRH stimulated POMC promoter activity (3.5-fold increase) as well as cAMP generation and ACTH secretion in a dose- and time-dependent manner, with the maximal effect being observed 3-5 h after the start of incubation. Catecholamines, especially epinephrine (10 nM and above), also stimulated all parameters, although less potently than CRH, and the effect was mimicked by the beta-, but not alpha-adrenergic, agonist, suggesting the involvement of the beta-adrenergic receptor. The combined effects of epinephrine and CRH were greater in all parameters than those of CRH alone, and the effects of both hormones were completely blocked by H89, an inhibitor of protein kinase A. Vasopressin and angiotensin II showed minimal effects on POMC expression. Our results suggest that 1) catecholamines, as well as CRH, positively regulate the POMC gene at physiological concentrations; 2) the cAMP-PKA system is the common intracellular signaling pathway for CRH and catecholamines; and 3) vasopressin and angiotensin II also have weak but significant stimulatory effects on POMC promoter activity.
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Affiliation(s)
- Y Aoki
- First Department of Internal Medicine, Nagoya University School of Medicine, Showa-ku, Japan
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45
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Aoki Y, Iwasaki Y, Katahira M, Oiso Y, Saito H. Regulation of the rat proopiomelanocortin gene expression in AtT-20 cells. II: Effects of the pituitary adenylate cyclase-activating polypeptide and vasoactive intestinal polypeptide. Endocrinology 1997; 138:1930-4. [PMID: 9112389 DOI: 10.1210/endo.138.5.5116] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal polypeptide (VIP), members of the glucagon-secretin family, have recently been suggested to be involved in the regulation of corticotropin (ACTH) secretion. In this study, we examined the effects of both peptides on POMC gene expression. Using AtT20PL, a clone of the AtT20 mouse corticotroph tumor cells stably transfected with 0.7 kb of the rat POMC 5' promoter-luciferase fusion gene, the effects of both peptides on the POMC promoter activity were estimated by a luciferase assay. PACAP stimulated POMC 5' promoter activity as well as cAMP generation and ACTH secretion in a dose- and time-dependent manner, with the maximal effect being observed 3 h after the start of incubation. A similar effect was observed with VIP. Although the combined effects of PACAP/CRH or VIP/CRH were greater than that of either hormone alone, no such effect was observed between PACAP and VIP. Furthermore, RT-PCR analysis showed the presence of only the PVR3 receptor subtype in this cell line, which is known to have a similar affinity to PACAP and VIP, indicating that both peptides exert their effects through the same receptor. In contrast to the effect of CRH, which was completely abolished by a protein kinase A inhibitor H89, the effects of PACAP/VIP on POMC expression persisted during H89 treatment, suggesting the involvement of alternative intracellular signaling pathway(s) distinct from the protein kinase A system. Our results suggest that PACAP and VIP have positive effects on POMC gene expression and that multiple signaling pathways are involved in the transcriptional event.
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Affiliation(s)
- Y Aoki
- First Department of Internal Medicine, Nagoya University School of Medicine, Showa-ku, Japan
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46
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Kurihara Y, Nagata T, Imai T, Hiwatashi A, Horiuchi M, Sakakibara S, Katahira M, Okano H, Uesugi S. Structural properties and RNA-binding activities of two RNA recognition motifs of a mouse neural RNA-binding protein, mouse-Musashi-1. Gene 1997; 186:21-7. [PMID: 9047340 DOI: 10.1016/s0378-1119(96)00673-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
mouse-Musashi-1 (m-Msi-1) is an RNA-binding protein, abundantly expressed in the developing mammalian central nervous system (CNS). m-Msi-1 contains two RNA recognition motifs (RRMs). In this study, we found that the N-terminal RRM of m-Msi-1 (MMA) binds strongly to poly(G) and weakly to poly(U) in a way similar to that of the full-length m-Msi-1 protein characterized previously. The C-terminal RRM of m-Msi-1 (MMB), however, does not bind to RNA. In addition, the circular dichroism (CD) spectra of the two RRMs showed that the alpha-helical content of MMA is significantly higher than that of MMB, indicating that some differences in the secondary structure may be responsible for the distinct RNA binding properties of MMA and MMB.
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Affiliation(s)
- Y Kurihara
- Department of Bioengineering, Faculty of Engineering, Yokohama National University, Japan
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47
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Abstract
The properties of a mutant hammerhead ribozyme system, which consists of two RNA oligomer strands and in which stem II is deleted (replaced with a UUUU loop), are described. The effects of temperature, pH, and metal ions on the cleavage reaction were similar to those for the parent ribozyme with stem II. The mutant ribozyme showed a much lower cleavage rate (kcat = 0.04 min-1) in the presence of 10 mM MgCl2, where the parent ribozyme showed full cleavage activity. However, increasing the concentration of MgCl2 from 10 to 100 mM restored the cleavage activity of the mutant ribozyme to the original level (kcat = 0.2 min-1). CD titration experiments with MgCl2 using a noncleavable substrate were carried out. Deletion of stem II resulted in an about 20-fold reduction of the apparent Mg2+ binding affinity when the Mg2+ concentrations of half-saturation are compared. The results were analyzed by curve-fitting analysis and compared with those for the parent ribozyme. The analysis showed that the Mg2+ concentration dependence data in CD and cleavage experiments for the mutant enzyme can be explained by a two Mg2+ ion binding mechanism. These results that stem II is important for maintaining the conformation of the catalytic core suitable for Mg2+ binding.
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Affiliation(s)
- T Sakamoto
- Department of Bioengineering, Faculty of Yokohama National University
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48
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Nirasawa S, Nishino T, Katahira M, Uesugi S, Hu Z, Kurihara Y. Structures of heat-stable and unstable homologues of the sweet protein mabinlin. The difference in the heat stability is due to replacement of a single amino acid residue. Eur J Biochem 1994; 223:989-95. [PMID: 8055976 DOI: 10.1111/j.1432-1033.1994.tb19077.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
There are several analogues of the sweet protein mabinlin. In previous studies, we purified the heat-stable analogue, mabinlin II, from the seeds of Capparis masaikai Lévl. and determined its amino acid sequence [Liu, X., Maeda, S., Hu, Z., Aiuchi, T., Nakaya, K. & Kurihara, Y. (1993) Eur. J. Biochem. 211, 281-287] and the disulfide structure [Nirasawa, S., Liu, X., Nishino, T. & Kurihara, Y. (1993) Biochim. Biophys. Acta 1202, 277-280]. We have now purified four additional homologues of mabinlin. The sweet activities of mabinlin III and mabinlin IV were unchanged by incubation for 1 h at 80 degrees C, as was found previously for mabinlin II, while the sweet activity of mabinlin I-1 was completely abolished by a 1-h incubation at 80 degrees C. The circular dichroic spectrum showed that alpha-helical structures of mabinlins II-IV were unchanged by the 1-h incubation at 80 degrees C, while the alpha-helical structures of mabinlin I-1 were completely destroyed by the 1-h incubation in parallel with the decrease of the sweet activity. To compare the structures of the heat-stable and unstable homologues, we determined their amino acid sequences and the disulfide array. The positions of four disulfide bridges of mabinlin I-1 were the same as those of mabinlin II, suggesting that the disulfide bridges do not contribute to the difference in the heat stability among the homologues. There was a high similarity among amino acid sequences of the homologoues. Only three amino acid residues (A-chain residues at positions 22 and 32 and B-chain residue at position 47) were different between mabinlin I-1 and mabinlin III. A-chain residue at position 32 was lacking in mabinlin IV and the A-chain residue at position 22 was identical in both mabinlin I-1 and mabinlin II. The B-chain residue at position 47 was the only residue present in all three heat-stable homologues (mabinlins II-IV) and is not present in the unstable homologue (mabinlin I-1). This suggests that the difference in the heat stability of mabinlin is due to the difference in a B-chain residue at position 47; the difference in the heat-stable homologues is due to the presence of an arginine residue and the difference of the unstable homologue is due to the presence of glutamine.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- S Nirasawa
- Department of Chemistry, Faculty of Education, Yokohama National University, Japan
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49
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Katahira M, Kanagawa M, Sato H, Uesugi S, Fujii S, Kohno T, Maeda T. Formation of sheared G:A base pairs in an RNA duplex modelled after ribozymes, as revealed by NMR. Nucleic Acids Res 1994; 22:2752-9. [PMID: 7519767 PMCID: PMC308244 DOI: 10.1093/nar/22.14.2752] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The thermal stability and structure of an RNA duplex, r(GGACGAGUCC)2, the base sequence of which was modelled after both a hammerhead ribozyme and a lead ribozyme, were studied by CD and NMR. We previously demonstrated that the corresponding DNA duplex, d(GGACGAGTCC)2, formed unique 'sheared' G:A base pairs, where an amino proton, instead of an imino proton, of G is involved in the hydrogen bonding, and G and A bases are arranged 'side by side' instead of 'head to head' (Nucleic Acids Res. (1993) 21, 5418-5424). CD melting profiles showed that the RNA duplex is thermally more stable than the corresponding DNA duplex. NMR studies revealed that sheared G:A base pairs are formed in the RNA duplex, too, although the overall structure of the RNA is the A form, which differs from the B form taken on by the corresponding DNA. A model building study confirmed that sheared G:A base pairs can be accommodated in the double helical structure of the A form. A difference between the RNA and DNA duplexes in the stacking interaction involving G:A mismatch bases is also suggested. The demonstration that sheared G:A base pairs can be formed not only in DNA but also in RNA suggests that this base pairing plays an important role regarding the RNA structure.
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Affiliation(s)
- M Katahira
- Department of Bioengineering, Faculty of Engineering, Yokohama National University, Japan
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Katahira M, Sato H, Mishima K, Uesugi S, Fujii S. NMR studies of G:A mismatches in oligodeoxyribonucleotide duplexes modelled after ribozymes. Nucleic Acids Res 1993; 21:5418-24. [PMID: 8265358 PMCID: PMC310580 DOI: 10.1093/nar/21.23.5418] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The structures of two oligodeoxyribonucleotide duplexes, the base sequences of which were modelled after both a hammerhead ribozyme and a small metalloribozyme, were studied by NMR. Both duplexes contain adjacent G:A mismatches; one has a PyGAPu:PyGAPu sequence and the other a PyGAPy:PuGAPu sequence. It is concluded on the basis of many characteristic NOEs that in both duplexes G:A base pairs are formed in the unique 'sheared' form, where an amino proton instead of an imino proton of G is involved in the hydrogen bonding, and G and A bases are arranged 'side by side' instead of 'head to head'. A photo-CIDNP experiment, which gives unique and independent information on the solvent accessibility of nucleotide bases, also supports G:A base pairing rather than a bulged-out structure of G and A residues. This is the first demonstration that not only the PyGAPu:PyGAPu sequence but also the PyGAPy:PuGAPu sequence can form the unique sheared G:A base pairs. Taking the previous studies on G:A mismatches into account, the idea is suggested that a PyGA:GAPu sequence is a minimum and essential element for the formation of the sheared G:A base pairs. The sheared G:A base pairs in the PyGAPu:PyGAPu sequence are suggested to be more stable than those in the PyGAPy:PuGAPu sequence. This is explained rationally by the idea proposed above.
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Affiliation(s)
- M Katahira
- Department of Bioengineering, Faculty of Engineering, Yokohama National University, Japan
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