Involvement of g proteins and camp in the production of chitinolytic enzymes by Trichoderma harzianum
Braz. j. microbiol
;
33(2): 169-173, Apr.-Jun. 2002. ilus
Article
in English
| LILACS
| ID: lil-330266
RESUMO
The effect of G protein modulators and cyclic AMP (cAMP) on N-acetylglucosaminidase (NAGase) production was investigated during 84 h of growth of a Trichoderma harzianum strain in chitin-containing medium. Caffeine (5 mM), N6¾2'-O-dibutyryladenosine 3'5'-cyclic monophosphate sodium salt (dBcAMP) (1 mM) and 3-isobutyl-1-methylxanthine (IBMX) (2 mM) decreased extracellular NAGase activity by 80(per cent), 77(per cent) and 37(per cent), respectively. AlCl3/KF (100 µM/10 mM and 200 µM/ 20 mM) decreased the activity by 85(per cent)and 95(per cent), respectively. Cholera (10 µ/mL) and pertussis (20 µ/mL) toxins also affected NAGase activity, causing a decrease of approximately 75(per cent). Upon all treatments, protein bands of approximately 73 kDa, 68 kDa and 45 kDa had their signals diminished whilst a 50 kDa band was enhanced only by treatment with cholera and pertussis toxins. N-terminal sequencing analysis identified the 73 kDa and 68 kDa proteins as being T. harzianum NAGase in two different truncated forms whereas the 45 kDa band comprised a T. harzianum endochitinase. The 50 kDa protein showed sequence similarity to Coriolus vesicolor cellobiohydrolase. The above results suggest that a signaling pathway comprising G-proteins, adenylate cyclase and cAMP may be involved in the synthesis of T. harzianum chitinases.
Full text:
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Index:
LILACS (Americas)
Main subject:
Trichoderma
/
In Vitro Techniques
/
Chitinases
/
GTP-Binding Proteins
/
Enzymes
Language:
English
Journal:
Braz. j. microbiol
Journal subject:
Microbiology
Year:
2002
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Federal de Goiás/BR
/
Universidade de Brasilia/BR
/
Universidade de Brasília/BR
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