Differential HSC70 expression during asexual development of Neurospora crassa
Differential HSC70 expression during asexual development of Neurospora crassa
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DOI：
10.1099/00221287-143-11-3615
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发表时间：
1997-11-01
期刊：
影响因子：
2.8
通讯作者：
Rensing, L
中科院分区：
文献类型：
--
作者：
Fracella, F;Scholle, C;Rensing, L
通过双向凝胶电泳测定，在粗糙脉孢菌营养生长和产孢过程中，热休克蛋白家族成员的组成和热休克诱导表达发生了变化。Western blot和ELISA分析显示，组成型热休克蛋白70（HSC 70）在分生孢子气生菌丝和休眠分生孢子的最高金额。分生孢子萌发期间，HSC 70的含量减少，随后在营养生长期间增加。静止菌丝和气生菌丝的HSC 70水平最低。HSC 70的静止相依赖性减少伴随着其核定位的伴随增加，而在气生菌丝发育过程中没有发现核HSC 70的量的显着变化。气生菌丝发育过程中cAMP含量与HSC 70呈负相关。为了研究HSC 70表达和cAMP含量之间可能的因果关系，分析了腺苷酸环化酶缺陷突变体crisp（cr-l），其表现出低浓度的内源性cAMP。然而，与bdA菌株相比，该突变体显示出较低的组成型HSC 70水平。用20 μ M的8-溴-cAMP处理bd株和cr-1突变株，没有导致组成型HSC 70水平的显著变化，但导致热诱导的HSC/HSP 70水平的显著变化。在一个发育突变体（acon-2），这是有缺陷的分生孢子的分化步骤，在气生菌丝中的HSC 70的表达被延迟，直到第一个原孢子链观察。可以得出结论，HSC/HSP 70的差异表达不依赖于不同的核水平的HSC 70或cAMP浓度的变化，而是发育基因控制分生孢子。
The constitutive and the heat-shock-induced expression of members of heat-shock protein families changed during vegetative development and conidiation of Neurospora crassa as determined by two-dimensional gel electrophoresis. Western blot and ELISA analyses revealed the highest amounts of the constitutive heat-shock protein 70 (HSC70) in conidiating aerial hyphae and dormant conidia. During conidial germination the amount of HSC70 decreased and subsequently increased during vegetative growth. Stationary mycelia and young aerial hyphae exhibited the lowest HSC70 level. The stationary-phase-dependent decrease in HSC70 was accompanied by a concomitant increase in its nuclear localization, whereas no significant changes in the amount of nuclear HSC70 were found during aerial hyphae development. The cAMP content during aerial hyphae development was inversely correlated with that of HSC70. To examine possible causal relations between HSC70 expression and cAMP content, the adenylate-cyclase-deficient mutant crisp (cr-l) was analysed, which exhibits low concentrations of endogenous cAMP. This mutant, however, showed a lower constitutive HSC70 level, compared to the bdA strain. Treatment of the bd strain and cr-l mutant with 20 mu M 8-bromo-cAMP did not result in significant changes of the constitutive HSC70 level, but in the level of heat-induced HSC/HSP70. In a developmental mutant (acon-2) which is defective in a differentiation step toward conidiation, the expression of HSC70 in aerial hyphae was delayed until the first proconidial chains were observed. It is concluded that the differential expression of HSC/HSP70 does not depend on different nuclear levels of HSC70 or on changes in cAMP concentrations, but rather on developmental genes controlling conidiation.