In plants and animals, cryptochromes function as either photoreceptors or circadian clock components. We have examined the cryptochrome from the filamentous fungus Neurospora crassa and demonstrate that Neurospora cry encodes a DASH-type cryptochrome that appears capable of binding flavin adenine dinucleotide (FAD) and methenyltetrahydrofolate (MTHF). The cry transcript and CRY protein levels are strongly induced by blue light in a wc-1-dependent manner, and cry transcript is circadianly regulated, with a peak abundance opposite in phase to frq. Neither deletion nor overexpression of cry appears to perturb the free-running circadian clock. However, cry disruption knockout mutants show a small phase delay under circadian entrainment. Using electrophoretic mobility shift assays (EMSA), we show that CRY is capable of binding single- and double-stranded DNA (ssDNA and dsDNA, respectively) and ssRNA and dsRNA. Whole-genome microarray experiments failed to identify substantive transcriptional regulatory activity of cry under our laboratory conditions
