Sepúlveda M Rosario, Berrocal María, Marcos Daniel, Wuytack Frank, Mata Ana M
Departamento de Bioquímica y Biología Molecular y Genética, Facultad de Ciencias, Universidad de Extremadura, Badajoz, Spain.
J Neurochem. 2007 Nov;103(3):1009-18. doi: 10.1111/j.1471-4159.2007.04794.x. Epub 2007 Aug 6.
Membrane fractions of pig cerebellum show Ca2+-ATPase activity and Ca2+ transport due to the presence of the secretory pathway Ca2+-ATPase (SPCA). The SPCA1 isoform shows a wide distribution in the neurons of pig cerebellum, where it is found in the Golgi complex of the soma of Purkinje, stellate, basket and granule cells, and also in more distal components of the secretory pathway associated with a synaptic localization such as in cerebellar glomeruli. The SPCA1 may be involved in loading the Golgi complex and the secretory vesicles of these specific neuronal cell types with Ca2+ and also Mn2+. This study of the cellular and subcellular localization of SPCA1 pumps relative to the sarco(endo) plasmic reticulum Ca2+-ATPase and plasma membrane Ca2+-ATPase pumps hints to a possible specific role of SPCA1 in controlling the luminal secretory pathway Ca2+ (or Mn2+) levels as well as the local cytosolic Ca2+ levels. In addition, it helps to specify the zones that are most vulnerable to Ca2+ and/or Mn2+ dyshomeostasis, a condition that is held responsible of an increasing number of neurological disorders.
猪小脑的膜组分由于存在分泌途径Ca2+-ATP酶（SPCA）而表现出Ca2+-ATP酶活性和Ca2+转运。SPCA1亚型在猪小脑神经元中分布广泛，在浦肯野细胞、星状细胞、篮状细胞和颗粒细胞胞体的高尔基体中以及与突触定位相关的分泌途径的更远端成分如小脑小球中均有发现。SPCA1可能参与了这些特定神经元细胞类型的高尔基体和分泌囊泡的Ca2+以及Mn2+装载。这项关于SPCA1泵相对于肌质（内质）网Ca2+-ATP酶和质膜Ca2+-ATP酶泵的细胞和亚细胞定位的研究表明，SPCA1在控制管腔分泌途径Ca2+（或Mn2+）水平以及局部胞质Ca2+水平方面可能具有特定作用。此外，它有助于明确最易受Ca2+和/或Mn2+稳态失调影响的区域，这种情况与越来越多的神经疾病有关。
