scholarly journals Lupus antiribosomal P antisera contain antibodies to a small fragment of 28S rRNA located in the proposed ribosomal GTPase center.

1991 ◽  
Vol 174 (3) ◽  
pp. 507-514 ◽  
Author(s):  
J L Chu ◽  
N Brot ◽  
H Weissbach ◽  
K Elkon
Keyword(s):  
28S Rrna ◽  
Direct Role ◽  
Autoantibody Production ◽  
Antisense Orientation ◽  
Form Part ◽  
Rna Fragments ◽  
P Proteins ◽  
Ribosomal P ◽  
Made In

The ribosomal P proteins are necessary for GTPase activity during protein synthesis. In addition to antibodies to the P proteins, sera from lupus patients contain anti-rRNA activity. To determine whether lupus antiribosomal sera recognize the region of 28S rRNA recently proposed to form part of the ribosomal GTPase center, an rRNA fragment corresponding to nucleotides (nt) 1922-2020 was transcribed in vitro and tested for antigenicity. 18 of 24 (75%) lupus sera containing anti-P antibodies, but only 2 of 24 (8%) lupus sera without anti-P, immunoprecipitated this rRNA fragment (p less than 0.001). The binding was specific, since no significant differences were observed between anti-P positive and negative lupus sera in binding to the RNA fragment transcribed in the antisense orientation or to a control region of rRNA. The majority of sera tested protected a rRNA fragment of approximately 68 nucleotides. To evaluate the fine specificity of the anti-28S antibodies, deletions and site-directed mutations were made in the RNA fragment. The anti-28S antisera required nt 1944-1955 for recognition and were remarkably sensitive to destabilizing as well as nondestabilizing mutations in the stems of the RNA fragments. Detection of antiprotein and anti-RNA antibodies directed against a functionally related domain in the ribosome, together with the remarkable specificity of anti-28S antibodies, strongly suggests a direct role for this region of the ribosome in initiating and/or maintaining antiribosomal autoantibody production.

scholarly journals Modulation of Cardiocyte Functional Activity by Antibodies against Trypanosoma cruzi Ribosomal P2 Protein C Terminus

2000 ◽  
Vol 68 (9) ◽  
pp. 5114-5119 ◽  
Author(s):  
P. Sepulveda ◽  
P. Liegeard ◽  
G. Wallukat ◽  
M. J. Levin ◽  
M. Hontebeyrie
Keyword(s):  
Trypanosoma Cruzi ◽  
Functional Activity ◽  
Molecular Mimicry ◽  
Host Cells ◽  
Cardiac Pathology ◽  
Epitope Recognition ◽  
C Terminus ◽  
P Proteins ◽  
Ribosomal P

ABSTRACT Antibodies against the Trypanosoma cruzi ribosomal P2β protein (TcP2β) have been associated with the chronic cardiac pathology of Chagas' disease in humans. Using synthetic peptides spanning the entire TcP2β molecule, we investigated their epitope recognition by antibodies from mice chronically infected with T. cruzi and from mice immunized with two recombinant TcP2βs. We found clear differences in epitope recognition between antibodies from T. cruzi-infected mice and mice immunized with two different recombinant TcP2βs associated with different schedules of immunization. Major epitopes recognized by antibodies from mice immunized with recombinant glutathioneS-transferase (GST) or histidine (Hist) fusion TcP2β (GST-TcP2β or Hist-TcP2β) are located in the central and hinge regions of the molecule. Nevertheless, mice immunized with Hist-TcP2β were also able to elicit antibodies against the TcP2β C terminus, a region which is highly conserved in both T. cruzi and mammal ribosomal P proteins. Strikingly, antibodies from infected animals recognized only the TcP2β C terminus. By using these antisera with distinct profiles of epitope recognition, it could be shown that only C terminus-specific antibodies were able to increase the beating frequency of cardiomyocytes from neonatal rats in vitro by selective stimulation of the β1-adrenergic receptor. Thus, antibodies against the TcP2β C terminus elicited in the absence of infection are able to modulate a functional activity of host cells through a molecular mimicry mechanism.

The acidic ribosomal protein P2 from Euplotes octocarinatus is phosphorylated at its N-terminal domain

2014 ◽  
Vol 92 (1) ◽  
pp. 23-32
Author(s):  
Miaoqing Hu ◽  
Luqin Li ◽  
Jianbing Chao ◽  
Yaqin Zhao ◽  
Zhiyun Zhang ◽  
...  
Keyword(s):  
Ribosomal Protein ◽  
Phosphorylation Site ◽  
Elongation Factor ◽  
Native Page ◽  
Terminal Domain ◽  
Elongation Factor 2 ◽  
P Proteins ◽  
Euplotes Octocarinatus ◽  
Ribosomal P

The eukaryotic acid ribosomal P0, P1, and P2 proteins share a conserved flexible C-terminal tail that is rich in acidic residues, which are involved in the interaction with elongation factor 2 during protein synthesis. Our previous work suggested that the acidic ribosomal P proteins from Euplotes octocarinatus have a special C-terminal domain. To further understand this characteristic feature, both P2 and elongation factor 2 from E. octocarinatus were overexpressed, for the first time, in Escherichia coli in this study. GST pull-down assay indicated that P2 protein from E. octocarinatus (EoP2) interacted specifically with the N-terminal domain of elongation factor 2 from E. octocarinatus (EoEF-2) in vitro. The interacting part of EoP2 is in the C-terminal domains, consistent with the observation in other organisms. Phosphorylation of the recombinant EoP2 was performed in vitro using multiple methods such as 31P-NMR spectroscopy, native PAGE, and Phos-tagTM SDS-PAGE. Results showed that ribosomal protein EoP2 was phosphorylated by casein kinase II at serine 21 located at the N terminus. This phosphorylation site identified in EoP2 is quite different from that of P2 from other organisms, in which the phosphorylation site is located in the conserved C-terminal region.

scholarly journals Biochemical Characterization of 60S Acidic Ribosomal P Proteins Associated with CK-II from Bamboo Shoots and Potent Inhibitors of Their Phosphorylation in Vitro.

1999 ◽  
Vol 22 (7) ◽  
pp. 667-673 ◽  
Author(s):  
Toshiro MAEKAWA ◽  
Seiji KOSUGE ◽  
Saki SAKAMOTO ◽  
Shinji FUNAYAMA ◽  
Kanki KOMIYAMA ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Bamboo Shoots ◽  
P Proteins ◽  
Ribosomal P

scholarly journals Multiplication of Ribosomal P-Stalk Proteins Contributes to the Fidelity of Translation

2017 ◽  
Vol 37 (17) ◽  
Author(s):  
Leszek Wawiórka ◽  
Eliza Molestak ◽  
Monika Szajwaj ◽  
Barbara Michalec-Wawiórka ◽  
Mateusz Mołoń ◽  
...  
Keyword(s):  
Stimulate Factor ◽  
Gtp Hydrolysis ◽  
Translational Machinery ◽  
Translation Fidelity ◽  
Landing Platform ◽  
Elevated Rate ◽  
P Proteins ◽  
Ribosomal P

ABSTRACT The P-stalk represents a vital element within the ribosomal GTPase-associated center, which represents a landing platform for translational GTPases. The eukaryotic P-stalk exists as a uL10-(P1-P2)2 pentameric complex, which contains five identical C-terminal domains, one within each protein, and the presence of only one such element is sufficient to stimulate factor-dependent GTP hydrolysis in vitro and to sustain cell viability. The functional contribution of the P-stalk to the performance of the translational machinery in vivo, especially the role of P-protein multiplication, has never been explored. Here, we show that ribosomes depleted of P1/P2 proteins exhibit reduced translation fidelity at elongation and termination steps. The elevated rate of the decoding error is inversely correlated with the number of the P-proteins present on the ribosome. Unexpectedly, the lack of P1/P2 has little effect in vivo on the efficiency of other translational GTPase (trGTPase)-dependent steps of protein synthesis, including translocation. We have shown that loss of accuracy of decoding caused by P1/P2 depletion is the major cause of translation slowdown, which in turn affects the metabolic fitness of the yeast cell. We postulate that the multiplication of P-proteins is functionally coupled with the qualitative aspect of ribosome action, i.e., the recoding phenomenon shaping the cellular proteome.

scholarly journals The phosphorylation sites of ribosomal P proteins from Saccharomyces cerevisiae cells by endogenous CK-2, PK60S and RAP protein kinases.

1997 ◽  
Vol 44 (2) ◽  
pp. 191-200 ◽  
Author(s):  
A Boguszewska ◽  
R Szyszka ◽  
N Grankowski
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinases ◽  
Synthetic Peptides ◽  
Kinetic Studies ◽  
Phosphorylation Sites ◽  
P Proteins ◽  
Polypeptide Chains ◽  
Ribosomal P

The phosphorylation sites of ribosomal acidic proteins (P proteins) from Saccharomyces cerevisiae were studied in vivo and in vitro by using CK-2, PK60S and RAP protein kinases. The three enzymes phosphorylate the last serine residues located in a highly conserved carboxyl end of the polypeptide chains. This was established by two-dimensional analysis of tryptic phosphopeptides from 32P-labelled proteins YP1 alpha, YP1 beta, YP2 alpha and YP2 beta, and by kinetic studies of the protein kinases with synthetic peptides corresponding to the fragments of endogenous ribosomal acidic polypeptides. In experiments with both endogenous P proteins and synthetic peptides as substrates protein kinase PK60S demonstrated unusual substrate specificity. In contrast to CK-2 and RAP protein kinases, PK60S phosphorylates predominantly two of the four P proteins, YP1 alpha and YP2 beta, with kinetic constants dependent on the primary structure of the N-terminal region of the polypeptide containing the target residue. The neutral amino acid, alanine, at position 3 in the peptide AAEESDDD (polypeptide fragments of YP1 beta and YP2 alpha) decreases the K(m) value more than 10-fold by comparison with the basic lysine residue at the same position in the peptide AKEESDDD (polypeptide fragments of YP1 alpha and YP2 beta).

NGHIÊN CỨU SỬ DỤNG MÀNG BAO SINH HỌC TỪ DỊCH CHIẾT VI KHUẨN Pseudomonas putida 199B ĐẾN KHÁNG NẤM Aspergilus flavus T1 TRONG QUÁ TRÌNH BẢO QUẢN HẠT GIỐNG NGÔ

2017 ◽  
Vol 126 (3C) ◽  
Author(s):  
Nguyễn Thỵ Đan Huyền ◽  
Lê Thanh Long ◽  
Trần Thị Thu Hà ◽  
Nguyễn Cao Cường ◽  
Nguyễn Hiền Trang
Keyword(s):  
Pseudomonas Putida ◽  
28S Rrna

Chủng T1 phân lập từ các mẫu ngô nếp NK66 nhiễm nấm mốc tự nhiên được sử dụng để nghiên cứu khả năng kháng nấm của dịch chiết vi khuẩn Pseudomonas putida 199B. Đặc điểm hình thái của chủng T1 đã được quan sát đại thể (màu sắc, hình dáng, kích thước khuẩn lạc) trên môi trường PDA và vi thể (hình dáng bào tử) trên kính hiển vi kết hợp so sánh với loài Aspergilus flavus đối chứng. Kết quả phân tích trình tự gen mã hóa 28S rRNA của chủng T1 cho thấy sự tương đồng trình tự cao với các trình tự tương ứng của loài Aspergilus flavus trên ngân hàng gen. Kết quả khảo sát ảnh hưởng của dịch chiết vi khuẩn P. putida lên sự phát triển của nấm A.  flavus gây bệnh trên hạt ngô sau thu hoạch và bảo quản ở điều kiện in vitro cho thấy, ở nồng độ P. putida 24% đã ức chế 74,50% sự phát triển đường kính tản nấm sau 10 ngày nuôi cấy, ức chế 79,63% sự hình thành sinh khối sợi nấm sau 7 ngày nuôi cấy. Ở điều kiện in vivo, sự nảy mầm của hạt giống ngô sau 30 ngày được tạo màng bao sinh học bằng dịch chiết vi khuẩn P. putida nồng độ 18% đạt 97,91%, tỉ lệ hạt nhiễm nấm mốc giảm còn 20% so với 72% ở mẫu đối chứng.

NGHIÊN CỨU ẢNH HƯỞNG CỦA CHITOSAN HOÀ TAN TRONG NƯỚC ĐẾN NẤM Colletotrichum musae D1 GÂY BỆNH THÁN THƯ TRÊN CHUỐI Ở ĐIỀU KIỆN IN VITRO

2016 ◽  
Vol 119 (5) ◽  
Author(s):  
Lê Thanh Long ◽  
Nguyễn Văn Toản ◽  
Nguyễn Văn Huế ◽  
Trang Sĩ Trung ◽  
Vũ Ngọc Bội
Keyword(s):  
Water Soluble ◽  
28S Rrna ◽  
Colletotrichum Musae

Chủng D1 phân lập từ các mẫu chuối có vết bệnh thán thư điển hình được sử dụng để nghiên cứu khả năng kháng nấm của chitosan hoà tan trong nước (Water-soluble chitosan_WSC) ở điều kiện in vitro. Kết quả phân tích trình tự gen mã hoá 28S rRNA của chủng D1 cho thấy tương đồng trình tự cao với các trình tự tương ứng của loài Colletotrichum musae và được ký hiệu là Colletotrichum musae D1. Kết quả các thí nghiệm đều cho thấy C. musae D1 rất nhạy cảm với WSC, hiệu lực ức chế tăng khi tăng nồng độ WSC xử lý ở điều kiện in vitro. Trên môi trường PDA, nồng độ 1,6% WSC ức chế hoàn toàn sự sinh trưởng của sợi nấm C. musae D1, nồng độ ức chế 50% (PIRG50) và nồng độ ức chế tối thiểu 90% (MIC90) tương ứng với nồng độ WSC 0,28% và 0,88%. Trong môi trường PDB, giá trị IC50 và MIC90 tương ứng là 0,11% và 0,43% và sự phát triển của sợi nấm C. musae D1 bị ức chế hoàn toàn ở nồng độ 0,8%. WSC không chỉ ức chế sự nảy mầm mà còn gây biến đổi bất thường bào tử nấm khi quan sát trên kính hiển vi.

Potential of Nanoparticles in Combating Candida Infections

2019 ◽  
Vol 16 (5) ◽  
pp. 478-491 ◽  
Author(s):  
Faizan Abul Qais ◽  
Mohd Sajjad Ahmad Khan ◽  
Iqbal Ahmad ◽  
Abdullah Safar Althubiani
Keyword(s):  
Targeted Delivery ◽  
Recent Progress ◽  
Antifungal Agents ◽  
Fungal Infections ◽  
Fold Increase ◽  
Antifungal Drugs ◽  
Low Toxicity ◽  
Candida Infections ◽  
Made In

Aims: The aim of this review is to survey the recent progress made in developing the nanoparticles as antifungal agents especially the nano-based formulations being exploited for the management of Candida infections. Discussion: In the last few decades, there has been many-fold increase in fungal infections including candidiasis due to the increased number of immunocompromised patients worldwide. The efficacy of available antifungal drugs is limited due to its associated toxicity and drug resistance in clinical strains. The recent advancements in nanobiotechnology have opened a new hope for the development of novel formulations with enhanced therapeutic efficacy, improved drug delivery and low toxicity. Conclusion: Metal nanoparticles have shown to possess promising in vitro antifungal activities and could be effectively used for enhanced and targeted delivery of conventionally used drugs. The synergistic interaction between nanoparticles and various antifungal agents have also been reported with enhanced antifungal activity.

scholarly journals Suppressor of cytokine signaling-1 mimetic peptides attenuate lymphocyte activation in the MRL/lpr mouse autoimmune model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jatin Sharma ◽  
Teresa D. Collins ◽  
Tracoyia Roach ◽  
Shiwangi Mishra ◽  
Brandon K. Lam ◽  
...  
Keyword(s):  
Intraperitoneal Administration ◽  
Lymphocyte Activation ◽  
Signal Propagation ◽  
Skin Lesions ◽  
Effector Memory ◽  
Cytokine Signaling ◽  
Suppressor Of Cytokine Signaling ◽  
Autoantibody Production ◽  
Ifn Γ

AbstractAutoimmune diseases are driven largely by a pathogenic cytokine milieu produced by aberrantly activated lymphocytes. Many cytokines, including interferon gamma (IFN-γ), utilize the JAK/STAT pathway for signal propagation. Suppressor of Cytokine Signaling-1 (SOCS1) is an inducible, intracellular protein that regulates IFN-γ signaling by dampening JAK/STAT signaling. Using Fas deficient, MRL/MpJ-Faslpr/J (MRL/lpr) mice, which develop lupus-like disease spontaneously, we tested the hypothesis that a peptide mimic of the SOCS1 kinase inhibitory region (SOCS1-KIR) would inhibit lymphocyte activation and modulate lupus-associated pathologies. Consistent with in vitro studies, SOCS1-KIR intraperitoneal administration reduced the frequency, activation, and cytokine production of memory CD8+ and CD4+ T lymphocytes within the peripheral blood, spleen, and lymph nodes. In addition, SOCS1-KIR administration reduced lymphadenopathy, severity of skin lesions, autoantibody production, and modestly reduced kidney pathology. On a cellular level, peritoneal SOCS1-KIR administration enhanced Foxp3 expression in total splenic and follicular regulatory T cells, reduced the effector memory/naïve T lymphocyte ratio for both CD4+ and CD8+ cells, and reduced the frequency of GL7+ germinal center enriched B cells. Together, these data show that SOCS1-KIR treatment reduced auto-reactive lymphocyte effector functions and suggest that therapeutic targeting of the SOCS1 pathway through peptide administration may have efficacy in mitigating autoimmune pathologies.

Sign in / Sign up

Export Citation Format

Share Document