INBA   12521
INSTITUTO DE INVESTIGACIONES EN BIOCIENCIAS AGRICOLAS Y AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Alkaline/Neutral-Invertases in Anabaena sp. PCC 7120 Sucrose hydrolysis in heterocysts is essential for diazotrophic growth
Autor/es:
WALTER A. VARGAS, CAROLINA NISHI, LAURA GIARROCCO AND GRACIELA L. SALERNO
Lugar:
Lake Arrowhead, California, USA
Reunión:
Workshop; 10th Molecular Biology of Cyanobacteria Workshop; 2010
Resumen:
<!-- /* Font Definitions */ @font-face {font-family:"Times New Roman , serif ;"; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-alt:"Times New Roman"; mso-font-charset:0; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:0 0 0 0 0 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> <!-- /* Font Definitions */ @font-face {font-family:"Times New Roman , serif ;"; panose-1:0 0 0 0 0 0 0 0 0 0; mso-font-alt:"Times New Roman"; mso-font-charset:0; mso-generic-font-family:roman; mso-font-format:other; mso-font-pitch:auto; mso-font-signature:0 0 0 0 0 0;} /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> <!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:595.3pt 841.9pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:35.4pt; mso-footer-margin:35.4pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> Alkaline/Neutral-Invertases in Anabaena sp. PCC 7120. Sucrose hydrolysis inheterocysts is essential for diazotrophic growthWalter A. Vargas, Carolina Nishi, Laura Giarrocco and Graciela L. Salerno, CIBCEBB-MdP, FIBA, Mar del Plata, ArgentinaSucrose metabolism has been studied in several cyanobacterial species, but itsphysiological role in these prokaryotic organisms has not been elucidated yet.Interestingly, in filamentous nitrogen-fixing strains, sucrose was proposed as thereduced-carbon molecule transported to heterocysts to support nitrogen fixation. Inagreement, several lines of evidence suggested that an interconnection between sucroseand glycogen metabolism is essential for carbon partitioning and nitrogen assimilationin heterocysts of Anabaena (Nostoc) sp. PCC 7120.We previously demonstrated that InvA and InvB, two functional alkaline/neutralinvertases, are present in Anabaena sp. PCC 7120 filaments. In this study wedemonstrate that the expression of invA and invB is differentially regulated by thenitrogen source. From our experiments, we also learned that sucrose hydrolysisrepresents a crucial event to sustain nitrogen assimilation inside heterocysts ofAnabaena sp. PCC 7120. Besides, when the expression of the heterocystic invertaseform was impaired, the mutant cells were unable to divide under diazotrophicconditions, and also presented a reduced rate of sucrose-glycogen conversion innitrogen step-down experiments. In conclusion, our results demonstrate for the first timethat sucrose metabolism inside heterocysts is essential for diazotrophic growth and thatsucrose hydrolysis is a key component for the sucrose-glycogen interconnectionpreviously suggested.Supported by PICT 21227, PIP 2008, UNMdP and FIBA.