Fungal cryptochrome with DNA repair activity reveals an early stage in cryptochrome evolution

Proc Natl Acad Sci U S A. 2015 Dec 8;112(49):15130-5. doi: 10.1073/pnas.1514637112. Epub 2015 Nov 17.

Abstract

DASH (Drosophila, Arabidopsis, Synechocystis, Human)-type cryptochromes (cry-DASH) belong to a family of flavoproteins acting as repair enzymes for UV-B-induced DNA lesions (photolyases) or as UV-A/blue light photoreceptors (cryptochromes). They are present in plants, bacteria, various vertebrates, and fungi and were originally considered as sensory photoreceptors because of their incapability to repair cyclobutane pyrimidine dimer (CPD) lesions in duplex DNA. However, cry-DASH can repair CPDs in single-stranded DNA, but their role in DNA repair in vivo remains to be clarified. The genome of the fungus Phycomyces blakesleeanus contains a single gene for a protein of the cryptochrome/photolyase family (CPF) encoding a cry-DASH, cryA, despite its ability to photoreactivate. Here, we show that cryA expression is induced by blue light in a Mad complex-dependent manner. Moreover, we demonstrate that CryA is capable of binding flavin (FAD) and methenyltetrahydrofolate (MTHF), fully complements the Escherichia coli photolyase mutant and repairs in vitro CPD lesions in single-stranded and double-stranded DNA with the same efficiency. These results support a role for Phycomyces cry-DASH as a photolyase and suggest a similar role for cry-DASH in mucoromycotina fungi.

Keywords: Phycomyces; cryptochrome; evolution; mucoromycotina; photolyase.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cryptochromes / genetics
  • Cryptochromes / physiology*
  • DNA Repair / physiology*
  • Evolution, Molecular*
  • Genes, Fungal
  • Phycomyces / genetics
  • Phycomyces / metabolism*
  • Pyrimidine Dimers

Substances

  • Cryptochromes
  • Pyrimidine Dimers