García-Rico Ramón O, Chávez Renato, Fierro Francisco, Martín Juan F
Institute of Biotechnology of León, Spain.
Int Microbiol. 2009 Jun;12(2):123-9.
Heterotrimeric G protein signaling regulates many processes in fungi, such as development, pathogenicity, and secondary metabolite biosynthesis. For example, the Galpha subunit Pga1 from Penicillium chrysogenum regulates conidiation and secondary metabolite production in this fungus. The dominant activating allele, pga1G42R, encoding a constitutively active Pga1 Galpha subunit, was introduced in Penicillium roqueforti by transformation, resulting in a phenotype characterized by low sporulation and slow growth. In this work, the effect of the constitutively active Pga1G42R Galpha subunit on conidial germination, stress tolerance, and roquefortine C production of P. roqueforti was studied. Pga1G42R triggered germination in the absence of a carbon source, in addition to negatively regulating thermal and osmotic stress tolerance. The presence of the Pga1G42R Galpha subunit also had an important effect on roquefortine C biosynthesis, increasing production and maintaining high levels of the mycotoxin throughout a culture period of 30 days. Together, the results suggest that G protein-mediated signaling participates in the regulation of these three processes in P. roqueforti.
异源三聚体G蛋白信号传导调控真菌中的许多过程，如发育、致病性和次级代谢产物生物合成。例如，产黄青霉的Gα亚基Pga1调控该真菌的分生孢子形成和次级代谢产物产生。通过转化将编码组成型活性Pga1 Gα亚基的显性激活等位基因pga1G42R引入罗克福特青霉，导致其表型特征为产孢量低和生长缓慢。在本研究中，研究了组成型活性Pga1G42R Gα亚基对罗克福特青霉分生孢子萌发、胁迫耐受性和罗克福汀C产生的影响。除了负向调节热胁迫和渗透胁迫耐受性外，Pga1G42R在无碳源的情况下触发萌发。Pga1G42R Gα亚基的存在对罗克福汀C生物合成也有重要影响，在整个30天的培养期内增加了该霉菌毒素的产量并维持在高水平。总之，结果表明G蛋白介导的信号传导参与罗克福特青霉这三个过程的调控。
