Distinct mechanisms regulating gene expression coexist within the fermentative pathways in Chlamydomonas reinhardtii.
ScientificWorldJournal
; 2012: 565047, 2012.
Article
em En
| MEDLINE
| ID: mdl-22792045
ABSTRACT
Under dark anoxia, the unicellular green algae Chlamydomonas reinhardtii may produce hydrogen by means of its hydrogenase enzymes, in particular HYD1, using reductants derived from the degradation of intercellular carbon stores. Other enzymes belonging to the fermentative pathways compete for the same reductants. A complete understanding of the mechanisms determining the activation of one pathway rather than another will help us engineer Chlamydomonas for fermentative metabolite production, including hydrogen. We examined the expression pattern of the fermentative genes PDC3, LDH1, ADH2, PFL1, and PFR1 in response to day-night cycles, continuous light, continuous darkness, and low or high oxygen availability, which are all conditions that vary on a regular basis in Chlamydomonas' natural environment. We found that all genes except PFL1 show daily fluctuations in expression, and that PFR1 differentiated itself from the others in that it is clearly responsive to low oxygen, where as PDC3, LDH1, and ADH2 are primarily under diurnal regulation. Our results provide evidence that there exist at least three different regulatory mechanisms within the fermentative pathways and suggest that the fermentative pathways are not redundant but rather that availability of a variety of pathways allows for a differential metabolic response to different environmental conditions.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Chlamydomonas reinhardtii
/
Regulação da Expressão Gênica de Plantas
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Fermentação
Idioma:
En
Revista:
ScientificWorldJournal
Assunto da revista:
MEDICINA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Itália