Ca2+ channel targeting in neuroendocrine cells

人体内的细胞通过释放能够刺激或抑制其他细胞的化学物质来相互交流。这种交流可以非常快，比如从大脑中的神经元释放神经递质，也可以相对缓慢，比如从神经内分泌细胞向血液中释放激素。这两种类型的释放都依赖于钙离子通过细胞膜上的毛孔或“通道”流入。因此，钙通道的功能对细胞间的通讯至关重要。特定的机制已经进化为将钙通道发送到特定的位置以执行其功能。我们在两种神经内分泌细胞中发现了一种新的钙通道变体。这种通道结构的差异可能有助于解释为什么神经元释放神经递质很快，而神经内分泌细胞释放神经激素相对较慢。我们建议进行实验，以确定这种钙通道变体是否在其他类型的神经内分泌细胞中发现，以及它是否也在神经元中发现。我们还建议尝试确定这种结构上的差异如何改变钙通道变体与导致化学信使释放的机制一起工作的方式。因此，我们提出的实验将帮助我们了解细胞释放神经递质和激素的机制。

Cells in the body communicate with one another by releasing chemicals that can excite or inhibit other cells. This communication can be very fast, as with the release of neurotransmitters from neurons in the brain, or it can be relatively slow, as with the release of hormones from neuroendocrine cells into the blood stream. Both types of release depend on the influx of calcium ions through pores or "channels" in the cell membrane. The function of calcium channels is therefore critical for intercellular communication. Specific mechanisms have evolved to send calcium channels to specific locations to perform their functions. We have found a new variant of a calcium channel in two types of neuroendocrine cells. This difference in channel structure may help to explain why release of neurotransmitters from neurons is fast, while release of neurohormones from neuroendocrine cells is relatively slow. We propose to do experiments to determine whether this calcium channel variant is found in other types of neuroendocrine cells and whether it is also found in neurons. We also propose to try to determine how this difference in structure changes the way the calcium channel variant works with the machinery that causes the release of chemical messengers. Our proposed experiments will therefore help us to understand the mechanisms by which cells release neurotransmitters and hormones.