A dynein-associated photoreceptor protein prevents ciliary acclimation to blue light

Light-responsive regulation of ciliary motility is known to be conducted through modulation of dyneins, but the mechanism is not fully understood. Here, we report a novel subunit of the two-headed f/I1 inner arm dynein, named DYBLUP, in animal spermatozoa and a unicellular green alga. This subunit contains a BLUF (sensors of blue light using FAD) domain that appears to directly modulate dynein activity in response to light. DYBLUP (dynein-associated BLUF protein) mediates the connection between the f/I1 motor domain and the tether complex that links the motor to the doublet microtubule. Chlamydomonas lacking the DYBLUP ortholog shows both positive and negative phototaxis but becomes acclimated and attracted to high-intensity blue light. These results suggest a mechanism to avoid toxic strong light via direct photoregulation of dyneins.

Automated summary

A novel subunit named DYBLUP has been discovered to modulate dynein activity in animal spermatozoa and a unicellular green alga through connecting the f/I1 motor domain and the tether complex. Chlamydomonas lacking the DYBLUP ortholog showed both positive and negative phototaxis, but became acclimated and attracted to high-intensity blue light, suggesting a mechanism to avoid toxic strong light via direct photoregulation of dyneins.