Involvement of G proteins and cAMP in the production of chitinolytic enzymes by Trichoderma harzianum

Brazilian Journal of Microbiology

Alexandre A.p. Firmino²  Cirano J. Ulhoa¹  Marcelo V. Sousa²  Edivaldo X. Ferreira Filho¹  Carlos A.o. Ricart² 

[1] ,Universidade de Brasilia Departamento de Biologia Celular Centro Brasileiro de Serviços e Pesquisas em ProteínasBrasília DF ,Brasil

关键词: Trichoderma;    N-acetylglucosaminidase;    chitinase;    cAMP;    G protein;    Trichoderma;    N-acetilglicosaminidase;    quitinase;    cAMP;    proteína G;   

DOI  :  10.1590/S1517-83822002000200015

来源: SciELO

【 摘 要 】

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), N6--2'-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%, 77% and 37%, respectively. AlCl3/KF (100 µM/10 mM and 200 µM/ 20 mM) decreased the activity by 85% and 95%, respectively. Cholera (10 µ/mL) and pertussis (20 µ/mL) toxins also affected NAGase activity, causing a decrease of approximately 75%. 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.

【 授权许可】

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