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Titolo:
OVER-PRODUCTION OF THE D1 PROTEIN OF PHOTOSYSTEM-II REACTION-CENTER IN THE CYANOBACTERIUM SYNECHOCOCCUS SP PCC-7942
Autore:
SOITAMO AJ; ZHOU G; CLARKE AK; OQUIST G; ARO EM; GUSTAFSSON P;
Indirizzi:
UNIV TURKU,DEPT BIOL SF-20500 TURKU FINLAND UMEA UNIV,DEPT PLANT PHYSIOL S-90187 UMEA SWEDEN
Titolo Testata:
Plant molecular biology
fascicolo: 2, volume: 26, anno: 1994,
pagine: 709 - 721
SICI:
0167-4412(1994)26:2<709:OOTDPO>2.0.ZU;2-7
Fonte:
ISI
Lingua:
ENG
Soggetto:
PSBA GENE FAMILY; ANACYSTIS-NIDULANS; ESCHERICHIA-COLI; EXPRESSION VECTORS; DISTINCT FORMS; LIGHT; CONSTRUCTION; MUTAGENESIS; SEQUENCES; PROMOTER;
Keywords:
GENE EXPRESSION; PHOTOSYNTHESIS; PROTEIN TURNOVER; PSBA; TAC PROMOTER;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Science Citation Index Expanded
Citazioni:
35
Recensione:
Indirizzi per estratti:
Citazione:
A.J. Soitamo et al., "OVER-PRODUCTION OF THE D1 PROTEIN OF PHOTOSYSTEM-II REACTION-CENTER IN THE CYANOBACTERIUM SYNECHOCOCCUS SP PCC-7942", Plant molecular biology, 26(2), 1994, pp. 709-721

Abstract

The unicellular cyanobacterium Synechococcus sp. PCC 7942 has three psbA genes encoding two different forms of the photosystem II reaction centre protein D1 (D1:1 and D1:2). The level of expression of these psbA genes and the synthesis of D1:1 and D1:2 are strongly regulated under varying light conditions. In order to better understand the regulatory mechanisms underlying these processes, we have constructed a strain of Synechococcus sp. PCC 7942 capable of over-producing psbA mRNA and D1 protein. In this study, we describe the over-expression of D1:1 using a tac-hybrid promoter in front of the psbAI gene in combination with lacI(Q) repressor system. Over-production of D1:1 was induced by growing cells for 12 h at 50 mu mol photons m(-2) s(-1) in the presenceof 40 or 80 mu g/ml IPTG. The amount of psbAI mRNA and that of D1:1 protein in cells grown with IPTG was three times and two times higher, respectively. A higher concentration of IPTG (i.e., 150 mu g/ml) did not further increase the production of the psbAI message or D1:1. The over-production of D1:1 caused a decrease in the level of D1:2 synthesised, resulting in most PSII reaction centres containing D1:1. However,the over-production of D1:1 had no effect on the pigment composition (chlorophyll a or phycocyanin/number of cells) or the light-saturated rate of photosynthesis. This and the fact that the total amounts of D1and D2 proteins were not affected by IPTG suggest that the number of PSII centres within the membranes remained unchanged. From these results, we conclude that expression of psbAI can be regulated by using thetac promoter and lacI(Q) system. However, the accumulation of D1:1 protein into the membrane is regulated by the number of PSII centres.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 01/12/20 alle ore 15:42:17