Unkles S E, Moon R P, Hawkins A R, Duncan J M, Kinghorn J R
Plant Molecular Genetics Unit, University of St. Andrews, Fife, U.K.
Gene. 1991 Apr;100:105-12. doi: 10.1016/0378-1119(91)90355-f.
Actin (ACT) in Phytophthora infestans is encoded by at least two genes, in contrast to unicellular and other filamentous fungi where there is a single gene. These genes (designated actA and actB) have been isolated from a genomic library of P. infestans. The complete nucleotide sequence of both genes has been determined. Unlike the actin-encoding genes (act) of other filamentous fungi, no introns are obvious in the coding region, a feature shared with the act genes of certain protists. Northern blotting and primer extension studies of the mRNA show that actA and actB are actively transcribed in mycelium, sporangia and germinating cysts but only at a low level in the case of actB. Both genes display bias in their codon usage. This is more extreme in actA. The deduced ACTB protein is strikingly similar to that of the Phytophthora megasperma actin and is more diverged from other actins than ACTA.
致病疫霉中的肌动蛋白（ACT）由至少两个基因编码，这与单细胞真菌和其他丝状真菌不同，它们只有一个肌动蛋白基因。这些基因（命名为actA和actB）已从致病疫霉的基因组文库中分离出来。已确定了这两个基因的完整核苷酸序列。与其他丝状真菌的肌动蛋白编码基因（act）不同，在编码区没有明显的内含子，这一特征与某些原生生物的act基因相同。对mRNA的Northern印迹和引物延伸研究表明，actA和actB在菌丝体、孢子囊和萌发的囊肿中均有活跃转录，但actB的转录水平较低。这两个基因在密码子使用上都存在偏好。actA中的这种偏好更为极端。推导的ACTB蛋白与大雄疫霉肌动蛋白的蛋白极为相似，并且与其他肌动蛋白相比，与ACTA的差异更大。
