Molecular cloning of the neutral trehalase gene from Kluyveromyces lactis and the distinction between neutral and acid trehalases |
| |
Authors: | F C Amaral P Van Dijck J R Nicoli J M Thevelein |
| |
Institution: | (1) Laboratorium voor Moleculaire Celbiologie, Katholieke Universiteit Leuven, Kardinaal Mercierlaan 92, B-3001 Leuven-Heverlee, Flanders, Belgium Tel. +32-16-321507; Fax +32-16-321979 e-mail johan.thevelein@bio.kuleuven.ac.be, BE;(2) Departamento de Bioquímica e Imunologia, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais, Caixa Postal 2486, 21941 Belo Horizonte-MG, Brazil, BR;(3) Departamento de Microbiologia, Instituto de Ciências Biologicas, Universidade Federal de Minas Gerais, Caixa Postal 2486, Belo Horizonte-MG, Brazil, BR |
| |
Abstract: | We cloned the Kluyveromyces lactis KlNTH1 gene, which encodes neutral trehalase. It showed 65.2% and 68.5% identity at nucleotide and amino acid sequence level, respectively,
with the Saccharomyces cerevisiae NTH1 gene. Multiple alignment of the predicted trehalase protein sequences from yeasts, bacteria, insects, and mammals revealed
two major domains of conservation. Only the yeast trehalases displayed in an N-terminal extension two consensus sites for
cAMP-dependent protein phosphorylation and a putative Ca2+-binding sequence. Gene disruption of the KlNTH1 gene abolished neutral trehalase activity and clearly revealed a trehalase activity with an acid pH optimum. It also resulted
in a high constitutive trehalose level. Expression of the KlNTH1 gene in an S. cerevisiae nth1Δ mutant resulted in rapid activation of the heterologous trehalase upon addition of glucose to cells growing on a nonfermentable
carbon source and upon addition of a nitrogen source to cells starved for nitrogen in a glucose-containing medium. In K. lactis, the same responses were observed except that rapid activation by glucose was observed only in early-exponential-phase cells.
Inactivation of K. lactis neutral trehalase by alkaline phosphatase and activation by cAMP in cell extracts are consistent with control of the enzyme
by cAMP-dependent protein phosphorylation.
Received: 19 March 1996 / Accepted: 15 October 1996 |
| |
Keywords: | Trehalase Trehalose Kluyveromyces lactis Protein phosphorylation NTH1 Glucose induction Glucose transport |
本文献已被 SpringerLink 等数据库收录! |
|