ASPERGILLUS-NIDULANS APSA (ANUCLEATE PRIMARY STERIGMATA) ENCODES A COILED-COIL PROTEIN REQUIRED FOR NUCLEAR POSITIONING AND COMPLETION OF ASEXUAL DEVELOPMENT
ASPERGILLUS-NIDULANS APSA (ANUCLEATE PRIMARY STERIGMATA) ENCODES A COILED-COIL PROTEIN REQUIRED FOR NUCLEAR POSITIONING AND COMPLETION OF ASEXUAL DEVELOPMENT
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DOI：
10.1083/jcb.128.4.485
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发表时间：
1995-02-01
影响因子：
7.8
通讯作者：
TIMBERLAKE, WE
中科院分区：
文献类型：
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作者：
FISCHER, R;TIMBERLAKE, WE
许多真菌能够通过极化细胞延伸形成菌丝或通过各向同性膨胀形成芽而生长。构巢曲霉无核的主要梗（apsA）突变体是有缺陷的核分布在菌丝和专门的，多细胞的生殖结构，称为分生孢子。apsA突变对菌丝生长的影响可以忽略不计，不像另一类核分布（nud）突变体。相比之下，它们几乎完全阻止分生孢子梗发育过程中产生的核进入初生芽或梗（芽成核）。初级小梗未能成核导致发育停滞和未能激活与下游发育步骤相关的转录程序。然而，偶尔在突变体中，细胞核进入初生芽，这一事件解除了发育障碍。因此，apsA功能有严格的发育要求，但仅在初生芽形成阶段。apsA编码一个183 kD的卷曲螺旋蛋白，与酿酒酵母NUM1p相似，是出芽过程中核迁移所必需的。
Many fungi are capable of growing by polarized cellular extension to form hyphae or by isotropic expansion to form buds. Aspergillus nidulans anucleate primary sterigmata (apsA) mutants are defective in nuclear distribution in both hyphae and in specialized, multicellular reproductive structures, called conidiophores. apsA mutations have a negligible effect on hyphal growth, unlike another class of nuclear distribution (nud) mutants. By contrast, they almost completely block entry of nuclei into primary buds, or sterigmata (bud nucleation), produced during development of conidiophores. Failure of the primary sterigmata to become nucleated results in developmental ar rest and a failure to activate the transcriptional program associated with downstream developmental steps. However, occasionally in mutants a nucleus enters a primary bud and this event relieves the developmental blockage. Thus, there is a stringent developmental requirement for apsA function, but only at the stage of primary bud formation. apsA encodes a 183-kD coiled-coil protein with similarity to Saccharomyces cerevisiae NUM1p, required for nuclear migration in the budding process.