scholarly journals Evolutionary analyses of the 12-kDa acidic ribosomal P-proteins reveal a distinct protein of higher plant ribosomes

1998 ◽  
Vol 95 (5) ◽  
pp. 2378-2383 ◽  
Author(s):  
K. Szick ◽  
M. Springer ◽  
J. Bailey-Serres

Mechanisms of action of cytokinins at the cellular and molecular levels are still unknown. Biological functions of cytokinins are presented through specific bioassay systems which are regarded as standard (delay of senescence of leaf tissue and stimulation of cell division) and which have been or may be biochemically investigated. These ‘biochemical functions’ of cytokinins are reviewed. The biochemical significance of the specific occurrence of cytokinins in transfer RNA molecules is discussed with respect to the question of the incorporation of labelled cytokinins into RNA molecules. Also, the significance of the cytokinin binding protein recently isolated from higher plant ribosomes is discussed.


1995 ◽  
Vol 179 (2) ◽  
pp. 193-202 ◽  
Author(s):  
L. Caponi ◽  
S. Pegoraro ◽  
V. Di Bartolo ◽  
P. Rovero ◽  
R. Revoltella ◽  
...  

Biochemistry ◽  
1997 ◽  
Vol 36 (47) ◽  
pp. 14439-14446 ◽  
Author(s):  
Reina Zambrano ◽  
Elisa Briones ◽  
Miguel Remacha ◽  
Juan P. G. Ballesta
Keyword(s):  

2000 ◽  
Vol 95 (2) ◽  
pp. 99-103 ◽  
Author(s):  
Kim Rayno ◽  
Morris Reichlin
Keyword(s):  

1999 ◽  
Vol 262 (2) ◽  
pp. 606-611 ◽  
Author(s):  
Patricia Bargis-Surgey ◽  
Jean-Pierre Lavergne ◽  
Philippe Gonzalo ◽  
Cecile Vard ◽  
Odile Filhol-Cochet ◽  
...  

1991 ◽  
Vol 174 (3) ◽  
pp. 507-514 ◽  
Author(s):  
J L Chu ◽  
N Brot ◽  
H Weissbach ◽  
K Elkon

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.


2011 ◽  
Vol 10 (3) ◽  
pp. 126-130 ◽  
Author(s):  
Patrícia Andrade de Macedo ◽  
Eduardo Ferreira Borba ◽  
Vilma dos Santos Trindade Viana ◽  
Elaine Pires Leon ◽  
Leonardo de Abreu Testagrossa ◽  
...  

Parasitology ◽  
2011 ◽  
Vol 138 (6) ◽  
pp. 736-747 ◽  
Author(s):  
VANINA GRIPPO ◽  
LETICIA L. NIBORSKI ◽  
KARINA A. GOMEZ ◽  
MARIANO J. LEVIN

SUMMARYPatients with chronic Chagas' Heart Disease (cChHD) develop an antibody response that is suspected to be involved in the cardiac pathogenesis. The response againstTrypanosoma cruziribosomal P proteins is of particular interest, as these antibodies can cross-react with host cardiac receptors causing electrophysiological alterations. To better understand the humoral anti-P response we constructed a single-chain variable fragment library derived from a cChHD patient. The variable heavy and light regions were amplified from bone-marrow RNA and subcloned into the vector pComb3X. The phage library was subsequently panned againstT. cruziribosomal P2βprotein (TcP2β). We obtained 3 different human recombinant antibodies that specifically reacted with TcP2βin ELISA and Western blots. Two of them reacted with the C-terminal region of TcP2β, peptide R13, as the recombinant autoanti-P antibodies from Systemic Lupus Erythematosus (SLE) patients. Interestingly, the third one was specific for TcP2βbut did not recognize R13, confirming the specific nature of the anti-P response in Chagas disease. Neither sequence nor VH usage similarities between Chagas and SLE anti-P autoantibodies were observed. Herein, the first human mAbs against TcP2βhave been obtained and characterized showing that the humoral anti-P response is directed against the parasite and does not include an autoimmune component.


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