cAMP-dependent protein kinase differentially regulates prestalk and prespore differentiation during Dictyostelium development.
cAMP-dependent protein kinase differentially regulates prestalk and prespore differentiation during Dictyostelium development.
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cAMP依赖性蛋白激酶在盘基网柄菌发育过程中差异性地调节前柄和前孢子分化。
作者：
S. Mann;R. Firtel
我们和其他人之前已经表明，camp依赖的蛋白激酶（PKA）活性对于盘基骨菌的聚集、诱导孢子前基因表达和多细胞发育至关重要。在本文中，我们进一步研究了这种调节作用。我们在多细胞阶段的特定细胞类型中过度表达了Dictyostelium PKA催化亚基（PKAcat），使用预柄和预孢子细胞类型特异性启动子使PKA活性在这些细胞中组成（独立于cAMP浓度）。为了研究其对细胞类型分化的影响，我们将表达pkacat的载体与从四种细胞类型特异性启动子中表达lacZ的报告构建物共转化：ecmA（特异性用于前柄A细胞）；ecmB（特异于前柄B和鼻涕虫的前样细胞）；ecmB δ 89（对茎细胞特异性）；SP60（孢子前细胞特异性）。通过对单个菌株在不同发育阶段β -半乳糖苷酶的组织学表达进行染色，我们能够解剖这些菌株的形态学变化，检查单个细胞类型的空间定位，并了解PKA在多细胞发育过程中的可能作用。从ecmA或ecmB预柄启动子中表达PKAcat导致异常发育，在丘期后不久停止，在尖端形成时产生具有圆形顶端突出的丘。预柄A和预柄B细胞定位于中心区域，顶丘位于末梢分化聚集体中，而前孢子细胞则表现出异常的空间定位。与发育停滞一致的是，这些土丘既没有形成成熟的孢子，也没有形成柄细胞，而且很少有细胞表达柄细胞特异性标记物。孢子前启动子PKAcat的表达导致孢子细胞形态发生异常，加速孢子细胞分化。当细胞被镀在琼脂上时，子实体形成了一个非常大的基区，主要含有孢子，和一个小的，不正常的果皮。成熟孢子细胞在14小时首次检测到，在18-20小时达到最高水平，而野生型菌株在24-26小时达到最高水平。当细胞被镀在滤光片上时，它们从一个大的基底区域产生一个细长的尖端，这个尖端继续延长为管状结构，并在末端产生一个“鼻涕虫状”结构。鼻涕虫主要由前柄细胞组成，少数前孢子细胞局限于鼻涕虫和管之间的连接处。随着鼻涕虫的迁移，在管中发现了这些前孢子细胞，而在鼻涕虫/管交界处出现了新的前孢子细胞，这表明鼻涕虫后部不断分化新的前孢子细胞。（摘要删节为400字）
We and others have previously shown that cAMP-dependent protein kinase (PKA) activity is essential for aggregation, induction of prespore gene expression and multicellular development in Dictyostelium. In this manuscript, we further examine this regulatory role. We have overexpressed the Dictyostelium PKA catalytic subunit (PKAcat) in specific cell types during the multicellular stages, using prestalk and prespore cell-type-specific promoters to make PKA activity constitutive in these cells (independent of cAMP concentration). To examine the effects on cell-type differentiation, we cotransformed the PKAcat-expressing vectors with reporter constructs expressing lacZ from four cell-type-specific promoters: ecmA (specific for prestalk A cells); ecmB (specific for prestalk B and anterior-like cells in the slug); ecmB delta 89 (specific for stalk cells); and SP60 (prespore-cell-specific). By staining for beta-galactosidase expression histologically at various stages of development in individual strains, we were able to dissect the morphological changes in these strains, examine the spatial localization of the individual cell types, and understand the possible roles of PKA during multicellular development. Expression of PKAcat from either the ecmA or ecmB prestalk promoters resulted in abnormal development that arrested shortly after the mound stage, producing a mound with a round apical protrusion at the time of tip formation. Prestalk A and prestalk B cells were localized in the central region and the apical mound in the terminal differentiated aggregate, while prespore cells showed an aberrant spatial localization. Consistent with a developmental arrest, these mounds did not form either mature spores or stalk cells and very few cells expressed a stalk-cell-specific marker. Expression of PKAcat from the prespore promoter resulted in abnormal morphogenesis and accelerated spore cell differentiation. When cells were plated on agar, a fruiting body was formed with a very large basal region, containing predominantly spores, and a small, abnormal sorocarp. Mature spore cells were first detected by 14 hours, with maximal levels reached by 18-20 hours, in contrast to 24-26 hours in wild-type strains. When cells were plated on filters, they produced an elongated tip from a large basal region, which continued to elongate as a tubular structure and produce a 'slug-like' structure at the end. The slug was composed predominantly of prestalk cells with a few prespore cells restricted to the junction between the 'slug' and tube. As the slug migrated, these prespore cells were found in the tube, while new prespore cells appeared at the slug/tube junction, suggesting a continual differentiation of new prespore cells at the slug's posterior.(ABSTRACT TRUNCATED AT 400 WORDS)
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盘基网柄菌中表面受体介导的腺苷酸环化酶激活。
DOI：
--
发表时间：
1986
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Theibert,A;Devreotes,PN
通讯作者：
Devreotes,PN
cAMP 依赖性蛋白激酶：多种酶家族的框架。
DOI：
10.1101/sqb.1988.053.01.018
发表时间：
1988
期刊：
Cold Spring Harbor symposia on quantitative biology
影响因子：
--
作者：
Taylor,SS;Buechler,JA;Slice,LW;Knighton,DK;Durgerian,S;Ringheim,GE;Neitzel,JJ;Yonemoto,WM;Sowadski,JM;Dospmann,W
通讯作者：
Dospmann,W
提高细胞内环磷酸腺苷水平的条件会促进盘基网柄菌孢子的形成。
DOI：
10.1111/j.1432-0436.1989.tb00726.x
发表时间：
1989
期刊：
Differentiation; research in biological diversity
影响因子：
--
作者：
Riley,BB;Jensen,BR;Barclay,SL
通讯作者：
Barclay,SL
影响因子：
56.9
作者：
DEVREOTES, P
通讯作者：
DEVREOTES, P
盘基网柄菌前孢子基因的发育和空间调控：顺式作用元件和 cAMP 诱导的、发育调控的 DNA 结合活性。
DOI：
10.1242/dev.113.3.947
发表时间：
1991
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Haberstroh,L;Galindo,J;Firtel,RA
通讯作者：
Firtel,RA