English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/116543
Título

Cloning, heterologous expression and biochemical characterization of plastidial sn-glycerol-3-phosphate acyltransferase from Helianthus annuus

AutorPayá-Milans, Miriam ; Venegas-Calderón, Mónica; Salas, Joaquín J. ; Garcés Mancheño, Rafael ; Martínez-Force, Enrique
Palabras claveHelianthus annuus
Plastids
Substrate specificity
Glycerol-3-phosphate acyltransferase
Sunflower
Fecha de publicación2015
EditorElsevier
CitaciónPhytochemistry 111: 27- 36 (2015)
Resumen© 2015 Elsevier Ltd. All rights reserved. The acyl-[acyl carrier protein]:sn-1-glycerol-3-phosphate acyltransferase (GPAT; E.C. 2.3.1.15) catalyzes the first step of glycerolipid assembly within the stroma of the chloroplast. In the present study, the sunflower (Helianthus annuus, L.) stromal GPAT was cloned, sequenced and characterized. We identified a single ORF of 1344 base pairs that encoded a GPAT sharing strong sequence homology with the plastidial GPAT from Arabidopsis thaliana (ATS1, At1g32200). Gene expression studies showed that the highest transcript levels occurred in green tissues in which chloroplasts are abundant. The corresponding mature protein was heterologously overexpressed in Escherichia coli for purification and biochemical characterization. In vitro assays using radiolabelled acyl-ACPs and glycerol-3-phosphate as substrates revealed a strong preference for oleic versus palmitic acid, and weak activity towards stearic acid. The positional fatty acid composition of relevant chloroplast phospholipids from sunflower leaves did not reflect the in vitro GPAT specificity, suggesting a more complex scenario with mixed substrates at different concentrations, competition with other acyl-ACP consuming enzymatic reactions, etc. In summary, this study has confirmed the affinity of this enzyme which would partly explain the resistance to cold temperatures observed in sunflower plants.
URIhttp://hdl.handle.net/10261/116543
DOI10.1016/j.phytochem.2014.12.028
Identificadoresdoi: 10.1016/j.phytochem.2014.12.028
issn: 0031-9422
Aparece en las colecciones: (IG) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
Postprint_Phytochemistry_2015_V111_P27.pdf4,08 MBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo
 

Artículos relacionados:


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.