Molecular and functional characterization of an invertase secreted by Ashbya gossypii

Tatiana Q. Aguiar, Cláudia Dinis, Frederico Magalhães, Carla Oliveira, Marilyn G. Wiebe, Merja Penttilä, Lucília Domingues (Corresponding Author)

Research output: Contribution to journalArticleScientificpeer-review

13 Citations (Scopus)

Abstract

The repertoire of hydrolytic enzymes natively secreted by the filamentous fungus Ashbya (Eremothecium) gossypii has been poorly explored. Here, an invertase secreted by this flavinogenic fungus was for the first time molecularly and functionally characterized. Invertase activity was detected in A. gossypii culture supernatants and cell-associated fractions. Extracellular invertase migrated in a native polyacrylamide gel as diffuse protein bands, indicating the occurrence of at least two invertase isoforms. Hydrolytic activity toward sucrose was approximately 10 times higher than toward raffinose. Inulin and levan were not hydrolyzed. Production of invertase by A. gossypii was repressed by the presence of glucose in the culture medium. The A. gossypii invertase was demonstrated to be encoded by the AFR529W (AgSUC2) gene, which is highly homologous to the Saccharomyces cerevisiae SUC2 (ScSUC2) gene. Agsuc2 null mutants were unable to hydrolyze sucrose, proving that invertase is encoded by a single gene in A. gossypii. This mutation was functionally complemented by the ScSUC2 and AgSUC2 genes, when expressed from a 2-μm-plasmid. The signal sequences of both AgSuc2p and ScSuc2p were able to direct the secretion of invertase into the culture medium in A. gossypii.

Original languageEnglish
Pages (from-to)524-534
Number of pages11
JournalMolecular Biotechnology
Volume56
Issue number6
DOIs
Publication statusPublished - 1 Jan 2014
MoE publication typeA1 Journal article-refereed

Keywords

  • Ashbya gossypii
  • Glucose repression
  • Invertase secretion
  • Secretion regulation

Fingerprint Dive into the research topics of 'Molecular and functional characterization of an invertase secreted by Ashbya gossypii'. Together they form a unique fingerprint.

  • Cite this