Laube G, Seidenbecher C I, Richter K, Dieterich D C, Hoffmann B, Landwehr M, Smalla K H, Winter C, Böckers T M, Wolf G, Gundelfinger E D, Kreutz M R
Institute for Medical Neurobiology, Otto-von-Guericke University, Magdeburg, Germany.
Mol Cell Neurosci. 2002 Mar;19(3):459-75. doi: 10.1006/mcne.2001.1078.
Caldendrin is the founder member of a recently discovered family of calmodulin-like proteins, which are highly abundant in brain. In this study we examined the organization of the murine and human caldendrin gene as well as the expression pattern of transcripts for caldendrin and two novel splice variants. In addition the distribution of caldendrin in rat brain has been assessed by immunohistochemistry. Caldendrin is localized to the somatodendritic compartment of a subpopulation of mainly principal neurons in brain regions with a laminar organization and is present only at a subset of mature excitatory synapses. Caldendrin immunoreactivity (IR) is tightly associated with the cortical cytoskeleton, enriched in the postsynaptic density (PSD) fraction, and associates late during development with the synaptic cytomatrix. The expression is highly heterogenous within cortex, with highest levels of caldendrin IR in layer III of the piriform and layer II/III of the somatosensory cortex. The segregated cortical distribution to areas, which represent the most important primary sensory systems of the rodent brain, may reflect different requirements for dendritic Ca2+-signaling in these neurons. The presence of caldendrin in the PSD of distinct synapses may have important implications for Ca2+-modulated processes of synaptic plasticity.
钙调蛋白是最近发现的一类钙调素样蛋白家族的创始成员，在大脑中含量极高。在本研究中，我们检测了小鼠和人类钙调蛋白基因的结构，以及钙调蛋白和两种新剪接变体的转录本表达模式。此外，还通过免疫组织化学评估了钙调蛋白在大鼠脑中的分布。钙调蛋白定位于具有分层结构的脑区中主要为主要神经元的一个亚群的树突体部分，并且仅存在于成熟兴奋性突触的一个子集中。钙调蛋白免疫反应性（IR）与皮质细胞骨架紧密相关，在突触后致密物（PSD）部分富集，并在发育后期与突触细胞基质相关联。其表达在皮质内高度异质，在梨状皮质的III层和体感皮质的II/III层中钙调蛋白IR水平最高。在代表啮齿动物大脑最重要的初级感觉系统的区域中，钙调蛋白在皮质的分布可能反映了这些神经元对树突状Ca2+信号的不同需求。在不同突触的PSD中存在钙调蛋白可能对Ca2+调节的突触可塑性过程具有重要意义。
