Figure 2.

Coupled mechanotransduction of cilia and ion channels. A. The basal body is a modified centriole that sits at the bottom of the cilia and provides the origin point for new cilia. They provide a symmetric template for the axoneme structure and dictate the position and orientation of the cilia, ensuring correct cilia-driven fluid flows and response to flow. B. The axoneme is the most prominent component of cilia consisting of nine microtubules. Its major function is cell signaling as the axoneme senses and coordinates mechanical and chemical responses, bending the cilia and altering downstream signaling. Intraflagellar transport brings cargo into the cilia along the axoneme with kinesin and out with dynein. C. In response to axoneme bending, stretch or calcium responsive ion channels, such as the polycystins (polycystic kidney diseases), open, allowing for calcium- or ATP-dependent signaling to occur inside the ciliary body. D. In response to calcium influx through the ion channel, downstream transcription factors (X) are phosphorylated and translocated to interact with the cytoskeleton, nucleus, and endoplasmic reticulum.