Arabidopsis Protein Kinase D6PKL3 Is Involved in the Formation of Distinct Plasma Membrane Aperture Domains on the Pollen Surface
Arabidopsis Protein Kinase D6PKL3 Is Involved in the Formation of Distinct Plasma Membrane Aperture Domains on the Pollen Surface
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DOI：
10.1105/tpc.18.00442
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发表时间：
2018-09-01
期刊：
影响因子：
11.6
通讯作者：
Dobritsa, Anna A.
中科院分区：
文献类型：
--
作者：
Lee, Byung Ha;Weber, Zachary T.;Dobritsa, Anna A.
发育中的花粉粒表面的某些区域表现出非常有限的花粉壁外壁沉积。这些区域产生花粉孔，其模式高度多样化，并且对单个物种具有特异性。拟南芥花粉具有三个等距的纵向孔。花粉孔形成的精确程度表明，为了创造它们，花粉采用了强大的机制来产生不同的细胞结构域。为了确定参与这一机制的参与者，我们筛选了天然拟南芥加入物，并发现了一个加入物Martuba，由于蛋白激酶D6PKL3的破坏，其孔形成异常。在花粉发育过程中，d6plkl3在未来开孔位点的三个质膜结构域积累。D6PKL3的定位和孔的形成都需要激酶的活性。适当的D6PKL3定位也依赖于磷酸肌苷相互作用的多基基序，并且我们确定了两种在未来孔位点特异性富集的磷酸肌苷。另一个已知的孔径因子INAPERTURATE POLLEN1在d6pkl3突变体的孔径位点上不能聚集，当d6pkl3定位错误时改变其定位，进而影响d6pkl3的定位。孔径因子的发现为细胞产生不同的膜结构域、形成细胞极性和表面图案的机制提供了重要的见解。
Certain regions on the surfaces of developing pollen grains exhibit very limited deposition of pollen wall exine. These regions give rise to pollen apertures, which are highly diverse in their patterns and specific for individual species. Arabidopsis thaliana pollen develops three equidistant longitudinal apertures. The precision of aperture formation suggests that, to create them, pollen employs robust mechanisms that generate distinct cellular domains. To identify players involved in this mechanism, we screened natural Arabidopsis accessions and discovered one accession, Martuba, whose apertures form abnormally due to the disruption of the protein kinase D6PKL3. During pollen development, D6PKL3 accumulates at the three plasma membrane domains underlying future aperture sites. Both D6PKL3 localization and aperture formation require kinase activity. Proper D6PKL3 localization is also dependent on a polybasic motif for phosphoinositide interactions, and we identified two phosphoinositides that are specifically enriched at the future aperture sites. The other known aperture factor, INAPERTURATE POLLEN1, fails to aggregate at the aperture sites in d6pkl3 mutants, changes its localization when D6PKL3 is mislocalized, and, in turn, affects D6PKL3 localization. The discovery of aperture factors provides important insights into the mechanisms cells utilize to generate distinct membrane domains, develop cell polarity, and pattern their surfaces.