Disease relevance of RPIA

• The present article describes the first patient with a deficiency of ribose-5-phosphate isomerase (RPI) (Enzyme Commission number 5.3.1.6) who presented with leukoencephalopathy and peripheral neuropathy [1].
• In experimental staphylococcal endocarditis, RP 59500 was as effective as vancomycin and significantly more effective than RPI (P < 0.01) and RPII (P < 0.05) [2].
• RPI and RPII demonstrated in vitro bacteriostatic and bactericidal synergy against a clinical strain of Staphylococcus aureus resistant to methicillin and susceptible to erythromycin [2].
• Evidence for the presence of phosphoriboisomerase and ribulose-1,5-diphosphate carboxylase in extracts of Desulfovibrio vulgaris [3].
• Recently cyclosporine A (CyA) has emerged as an available treatment for interstitial pneumonia in PM/DM, but its efficacy on RPIP is unclear [4].

High impact information on RPIA

• Deficient activity of RPI, one of the pentose-phosphate-pathway (PPP) enzymes, was demonstrated in fibroblasts [1].
• RPI gene-sequence analysis revealed a frameshift and a missense mutation [1].
• Renal and hepatic microsomes also have detectable levels of these enzymes except ribulose-5-phosphate epimerase and ribose-5-phosphate isomerase [5].
• However, kinetic studies of ribulose-5-phosphate 3-epimerase and phosphoriboisomerase suggested that the ribulose 5-phosphate produced by this pathway is converted mostly to xylulose 5-phosphate instead of to ribose 5-phosphate so that this pathway produces little phosphoribosylpyrophosphate [6].
• Inhibition of ribose-5-phosphate isomerase by 4-phosphoerythronate [7].

Biological context of RPIA

• During metaphase, RPI labeling was segregated into pairs of spheres and typical crescent-shaped structures; both were centrally located within the set of chromosomes [8].
• This typical 3-D organization of structures containing RPI relative to DNA is another strong example of the non-random organization of the genome during interphase and mitosis [8].
• For each step of the cell cycle, immunolabeled RPI molecules and DNA specifically stained with chromomycin A3 were simultaneously imaged at high resolution through numerous optical sections [8].
• IMGT, the international ImMunoGeneTics information system (http://imgt.cines.fr) provides a common access to expertly annotated data on the genome, proteome, genetics and structure of immunoglobulins (IG), T cell receptors (TR), major histocompatibility complex (MHC), and related proteins of the immune system (RPI) of human and other vertebrates [9].
• IMGT, the international ImMunoGeneTics information system (http://imgt.cines.fr) provides a common access to expertly annotated data on the genome, proteome, genetics and structure of immunoglobulins (IG), T cell receptors (TR), major histocompatibility complex (MHC), and related proteins of the immune system (RPI) of human and other vertebrates [10].

Anatomical context of RPIA

• 2. Both RPI and RPE were detected in all human tissues including red cells, lymphocytes and fibroblasts [11].
• Molecular characterization of RPI supports the view that a single amphibolic RPI enzyme functions in the oxidative and reductive pentose phosphate pathways of spinach plastids [12].
• In patients with appropriate erythropoietic responses to haemolysis (RPI > 2.0), shift reticulocytes display predominantly PNH phenotypes [13].
• In male gametogenesis, RPI-positive granules are present during meiotic prophase up to pachytene, as well as during the early and middle spermatid stages [14].
• Sixty nondiabetic coronary artery disease (CAD) patients submitted to coronary angiography were asked to rate (score 0 to 20) pain intensity (RPI) during their last major anginal episode having occurred prior to coronary angiography [15].

Associations of RPIA with chemical compounds

• Ribose-5-phosphate isomerase deficiency: new inborn error in the pentose phosphate pathway associated with a slowly progressive leukoencephalopathy [1].
• Ribose-5-phosphate isomerase (RPI) catalyses the interconversion of ribose-5-phosphate and ribulose-5-phosphate in the reductive and oxidative pentose phosphate pathways in plants [12].
• The association of ribulose-1,5-bisphosphate carboxylase with phosphoriboisomerase and phosphoribulokinase [16].
• A reversed phase ion-pairing high performance liquid chromatographic (RPIP-HPLC) method is developed for the separation of two phosphorus herbicides, Glufosinate and Glyphosate as well as Aminomethylphosphonic acid (AMPA), the major metabolite of Glyphosate [17].
• In this RPIP technique, the counter-ion, methanesulfonic acid, forms an ion-pair or association-complex with the ionic forms of the benzodiazepines, which are then retained by the reverse-phase C8 column [18].

Other interactions of RPIA

• The applicability of the method was demonstrated by the abnormal polyol concentrations observed in patients with transaldolase deficiency, ribose-5-phosphate isomerase deficiency and classical galactosaemia [19].

Analytical, diagnostic and therapeutic context of RPIA

• The relative three-dimensional co-location of RNA polymerase I (RPI) and DNA was studied using confocal laser scanning microscopy during interphase and all the steps of mitosis in human cancerous cells [8].
• We evaluated the in vivo activity and the diffusion of radiolabelled RP 57669 (RPI) and RP 54476 (RPII), the two components of the injectable streptogramin RP 59500, alone or in combination, in aortic vegetations from experimental endocarditis in rabbits [2].
• Via PCR with degenerate primers designed against microsequenced peptides, a hybridisation probe was obtained and used to isolate several cDNA clones which encode RPI [12].
• In direct-binding radioimmunoassay (RIA), affinity-purified anti-normal rabbit (NR) Fab autoAb cross-reacted with normal mouse (NM) Fab, ssDNA (but not dsDNA), poly(dA,dT), and RNA polymerase I (RPI) [20].
• Change in cardiovascular response pattern as a function of these activities, as well as the influence of a series of moderator variables on cardiovascular response, was assessed by examining heart rate (HR) and the EKG R-wave to ear pulse interval (RPI) relative to a pre-session baseline [21].

References