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Titolo:
Expression of psbA genes is regulated at multiple levels in the cyanobacterium Synechococcus sp PCC 7942
Autore:
Sippola, K; Aro, EM;
Indirizzi:
Univ Turku, Dept Biol, FIN-20014 Turku, Finland Univ Turku Turku FinlandFIN-20014 , Dept Biol, FIN-20014 Turku, Finland
Titolo Testata:
PHOTOCHEMISTRY AND PHOTOBIOLOGY
fascicolo: 6, volume: 71, anno: 2000,
pagine: 706 - 714
SICI:
0031-8655(200006)71:6<706:EOPGIR>2.0.ZU;2-N
Fonte:
ISI
Lingua:
ENG
Soggetto:
II REACTION-CENTER; HIGH LIGHT-INTENSITY; SP STRAIN PCC-7942; D1 PROTEIN-DEGRADATION; PHOTOSYSTEM-II; 2 FORMS; SYNECHOCYSTIS PCC-6803; ELECTRON-TRANSPORT; OVER-PRODUCTION; DISTINCT FORMS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
49
Recensione:
Indirizzi per estratti:
Indirizzo: Aro, EM Univ Turku, Dept Biol, FIN-20014 Turku, Finland Univ Turku TurkuFinland FIN-20014 iol, FIN-20014 Turku, Finland
Citazione:
K. Sippola e E.M. Aro, "Expression of psbA genes is regulated at multiple levels in the cyanobacterium Synechococcus sp PCC 7942", PHOTOCHEM P, 71(6), 2000, pp. 706-714

Abstract

In cyanobacterium Synechococcus sp. PCC 7942 the photosystem II reaction-center protein D1 is encoded by three psbA genes. The psbAI gene encodes D1:l protein, the form used for acclimated growth, and psbAII and psbAIII genes encode the stress-induced form, D1:2 protein. Strong light and low temperature have been shown to induce the expression of psbAII/III genes and down-regulate the expression of psbAI gene. Recently, we reported the involvement of reduced thiols in the up-regulation of psbAII/III genes. In this study, we have analyzed the regulation of psbA gene expression in Synechococcusfurther, at both the transcriptional and post-transcriptional levels. We show that the inhibitors of the photosynthetic electron-transfer chain, which have different effects on the redox state of the plastoquinone (PQ) pool,have similar effect on the transcription of psbA genes. The inhibitors 3-(3,4 dichlorophenyl)-1,1-dimethyturea (DCMU) and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) do not cause any changes in psbA gene expression when added under low-light conditions, but dramatically reduce the high-light induction of psbAII/III genes when added upon a high-light shift. Moreover, when the thiol reductant, dithiothreitol, is added to Synechococcus cells together with DCMU concomitant with the high-light shift, no inhibition of psbAII/ III gene up-regulation takes place, indicating that the thiolredox state rather than the redox state of the PQ pool regulates psbA genetranscription, We also provide evidence for post-transcriptional regulation of psbA gene expression, particularly, inhibition of translation of psbAItranscripts at high light, and demonstrate that the D1 protein synthesis and degradation processes are coregulated in Synechococcus.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/10/20 alle ore 10:13:01