Department of Dermatology, The First Affiliated Hospital of Dalian Medical University, Dalian, People's Republic of China.
Int J Mol Med. 2013 Jun;31(6):1343-8. doi: 10.3892/ijmm.2013.1352. Epub 2013 Apr 16.
Dimorphic switching requires fungal cells to undergo changes in polarized growth in response to environmental stimuli. The Ste20-related kinases are involved in signaling through mitogen-activated protein kinase pathways and in morphogenesis through the regulation of cytokinesis and actin-dependent polarized growth. In this report, we isolated and characterized an Ste20 homologue gene, designated SsSte20, from yeast-form Sporothrix schenckii (S. schenckii). The full length SsSte20 cDNA sequence is 2846 bp in size, and contains an open reading frame of 2505 bp encoding 835 amino acids. The predicted molecular mass of SsSte20 is 91.31 kDa with an estimated theoretical isoelectric point of 5.76. SsSte20 kinase domain shows 63% identity with that of Don3, a germinal centre kinase (GCK) from Ustilago maydis. Two exons and one intron are identified within the 2578 bp SsSte20 genomic DNA sequence of S. schenckii. Differential expression of the SsSte20 was demonstrated by real-time RT-PCR. The expression of SsSte20 was much higher in the yeast stage compared with that in the mycelial stage, which indicated that the SsSte20 may be involved in the pathogenesis of the yeast phase of S. schenckii.
二相性转换需要真菌细胞在响应环境刺激时经历极性生长的变化。Ste20 相关激酶参与有丝分裂原激活蛋白激酶途径的信号转导，并通过调节细胞分裂和肌动蛋白依赖性极性生长参与形态发生。在本报告中，我们从酵母形式的申克孢子丝菌（Sporothrix schenckii）中分离并鉴定了一个 Ste20 同源基因，命名为 SsSte20。SsSte20 cDNA 全长 2846 bp，包含一个 2505 bp 的开放阅读框，编码 835 个氨基酸。SsSte20 的预测分子质量为 91.31 kDa，理论等电点估计为 5.76。SsSte20 激酶结构域与 Ustilago maydis 中的生殖中心激酶（GCK）Don3 具有 63%的同一性。在申克孢子丝菌的 2578 bp SsSte20 基因组 DNA 序列中鉴定出两个外显子和一个内含子。通过实时 RT-PCR 证明了 SsSte20 的差异表达。与菌丝体阶段相比，酵母阶段的 SsSte20 表达水平要高得多，这表明 SsSte20 可能参与了申克孢子丝菌酵母相的发病机制。
