Vargas-Zapata R, Torres-González V, Sepúlveda-Saavedra J, Piñeyro-López A, Rechinger K B, Keizer-Gunnink I, Kiel J A, Veenhuis M
Departamento de Farmacología-Toxicología, Facultad de Medicina, U.A.N.L., Garza García, N.L., México.
Toxicon. 1999 Feb;37(2):385-98. doi: 10.1016/s0041-0101(98)00170-6.
Previously we demonstrated that peroxisomicine A1 (T-514), a plant toxin isolated from Karwinskia species, has a deteriorating effect on the integrity of peroxisomes of methylotrophic yeasts. Here we describe two strains of Hansenula polymorpha, affected in the normal utilization of methanol as sole source of carbon and energy due to peroxisomicine A1 treatment. The two strains isolated (L17 and RV31) grew poorly on methanol, apparently due to malfunctioning of their peroxisomes. Moreover, the cells displayed a high peroxisome turnover rate. We argue that the peroxisomicine A1 induced phenotype of both strains is due to a genomic mutation. Strain L17 was functionally complemented after transformation with a H. polymorpha genomic library. The complementing 2.8 kb DNA fragment did not contain a well-defined ORF and led us to speculate that it may contain regulatory sequences that, when present in multiple copies in the cell, result in a change of expression of specific genes, thus causing restoration of normal methylotrophic growth.
此前我们证明，从卡氏木属植物中分离出的植物毒素过氧新霉素A1（T-514）对甲基营养型酵母的过氧化物酶体完整性具有破坏作用。在此我们描述了两株多形汉逊酵母菌株，由于过氧新霉素A1处理，它们在以甲醇作为唯一碳源和能源的正常利用方面受到影响。分离出的两株菌株（L17和RV31）在甲醇上生长不良，显然是由于其过氧化物酶体功能异常。此外，细胞表现出较高的过氧化物酶体更新率。我们认为，两株菌株的过氧新霉素A1诱导表型是由于基因组突变所致。用多形汉逊酵母基因组文库转化后，L17菌株在功能上得到了互补。互补的2.8 kb DNA片段不包含明确的开放阅读框，这使我们推测它可能包含调控序列，当这些序列在细胞中以多拷贝形式存在时，会导致特定基因表达的改变，从而使正常的甲基营养型生长得以恢复。
