Gene

Biogenesis

Cell biology

Cilium

Biology

Compartment (ship)

Cell signaling

Signal transduction

Biochemistry

Second messenger system

Geology

Organelle

Oceanography

Signalling

Ciliopathies

Hedgehog

Hedgehog signaling pathway

Proteome

Phenotype

Nature Reviews Molecular Cell Biology

The primary cilium is a hair-like surface-exposed organelle of the eukaryotic cell that decodes a variety of signals - such as odorants, light and Hedgehog morphogens - by altering the local concentrations and activities of signalling proteins. Signalling within the cilium is conveyed through a diverse array of second messengers, including conventional signalling molecules (such as cAMP) and some unusual intermediates (such as sterols). Diffusion barriers at the ciliary base establish the unique composition of this signalling compartment, and cilia adapt their proteome to signalling demands through regulated protein trafficking. Much progress has been made on the molecular understanding of regulated ciliary trafficking, which encompasses not only exchanges between the cilium and the rest of the cell but also the shedding of signalling factors into extracellular vesicles.

Establishing and regulating the composition of cilia for signal transduction