Marcos Daniel, Sepulveda M Rosario, Berrocal María, Mata Ana M
Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz, Spain.
BMC Neurosci. 2009 Sep 7;10:112. doi: 10.1186/1471-2202-10-112.
Plasma membrane Ca2+-ATPases (PMCAs) are high affinity Ca2+ transporters actively involved in intracellular Ca2+ homeostasis. Considering the critical role of Ca2+ signalling in neuronal development and plasticity, we have analyzed PMCA-mediated Ca2+-ATPase activity and PMCA-isoform content in membranes from mouse cortex, hippocampus and cerebellum during postnatal development.
PMCA activity was detected from birth, with a faster evolution in cortex than in hippocampus and cerebellum. Western blots revealed the presence of the four isoforms in all regions, with similar increase in their expression patterns as those seen for the activity profile. Immunohistochemistry assays in cortex and hippocampus showed co-expression of all isoforms in the neuropil associated with synapses and in the plasma membrane of pyramidal cells soma, while cerebellum showed a more isoform-specific distribution pattern in Purkinje cells.
These results show an upregulation of PMCA activity and PMCA isoforms expression during brain development in mouse, with specific localizations mainly in cerebellum. Overall, our findings support a close relationship between the ontogeny of PMCA isoforms and specific requirements of Ca2+ during development of different brain areas.
质膜钙ATP酶（PMCAs）是高亲和力的钙转运蛋白，积极参与细胞内钙稳态。鉴于钙信号在神经元发育和可塑性中的关键作用，我们分析了出生后发育期间小鼠皮质、海马和小脑中质膜钙ATP酶介导的钙ATP酶活性及质膜钙ATP酶亚型含量。
出生时即检测到质膜钙ATP酶活性，皮质中的活性比海马和小脑的活性进化得更快。蛋白质免疫印迹显示所有区域均存在四种亚型，其表达模式的增加与活性谱相似。皮质和海马中的免疫组织化学分析显示，所有亚型在与突触相关的神经毡和锥体细胞体的质膜中共表达，而小脑在浦肯野细胞中显示出更多的亚型特异性分布模式。
这些结果表明，小鼠大脑发育过程中质膜钙ATP酶活性和质膜钙ATP酶亚型表达上调，主要在小脑中有特定定位。总体而言，我们的研究结果支持质膜钙ATP酶亚型的个体发生与不同脑区发育过程中钙的特定需求之间存在密切关系。
