Galactose metabolism and toxicity in Ustilago maydis.
Fungal Genet Biol
; 114: 42-52, 2018 05.
Article
en En
| MEDLINE
| ID: mdl-29580862
In most organisms, galactose is metabolized via the Leloir pathway, which is conserved from bacteria to mammals. Utilization of galactose requires a close interplay of the metabolic enzymes, as misregulation or malfunction of individual components can lead to the accumulation of toxic intermediate compounds. For the phytopathogenic basidiomycete Ustilago maydis, galactose is toxic for wildtype strains, i.e. leads to growth repression despite the presence of favorable carbon sources as sucrose. The galactose sensitivity can be relieved by two independent modifications: (1) by disruption of Hxt1, which we identify as the major transporter for galactose, and (2) by a point mutation in the gene encoding the galactokinase Gal1, the first enzyme of the Leloir pathway. The mutation in gal1(Y67F) leads to reduced enzymatic activity of Gal1 and thus may limit the formation of putatively toxic galactose-1-phosphate. However, systematic deletions and double deletions of different genes involved in galactose metabolism point to a minor role of galactose-1-phosphate in galactose toxicity. Our results show that molecular triggers for galactose toxicity in U. maydis differ from yeast and mammals.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Ustilago
/
Galactosa
Idioma:
En
Revista:
Fungal Genet Biol
Asunto de la revista:
GENETICA
/
MICROBIOLOGIA
Año:
2018
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Estados Unidos