The Photolyase/Cryptochrome Family of Proteins as DNA Repair Enzymes and Transcriptional Repressors

• Published in: Photochemistry and photobiology Vol. 93; no. 1; pp. 93 - 103
• Main Authors: Kavakli, Ibrahim Halil, Baris, Ibrahim, Tardu, Mehmet, Gül, Şeref, Öner, Haşimcan, Çal, Sibel, Bulut, Selma, Yarparvar, Darya, Berkel, Çağlar, Ustaoğlu, Pınar, Aydın, Cihan
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.01.2017
• Subjects: DNA repair; Drosophila; Enzymes; Light; Photobiology; Photoreceptors; Transcription factors
• ISSN: 0031-8655; 1751-1097
• DOI: 10.1111/php.12669

Light is a very important environmental factor that governs many cellular responses in organisms. As a consequence, organisms possess different kinds of light‐sensing photoreceptors to regulate their physiological variables and adapt to a given habitat. The cryptochrome/photolyase family (CPF) includes photoreceptors that perform different functions in different organisms. Photolyases repair ultraviolet‐induced DNA damage by a process known as photoreactivation using photons absorbed from the blue end of the light spectrum. On the other hand, cryptochromes act as blue light circadian photoreceptors in plants and Drosophila to regulate growth and development. In mammals, cryptochromes have light‐independent functions and are very important transcriptional regulators that act at the molecular level as negative transcriptional regulators of the circadian clock. In this review, we highlight current knowledge concerning the structural and functional relationships of CPF members. In this review, we highlight current knowledge concerning the structural and functional relationships of cryptochrome/photolyase family (CPF). Although 3D structures of the CPF members are very similar, they function differently depending on the type of the proteins. DNA photolyases, which absorb blue light energy to repair ultraviolet photoproducts in dsDNA, while CRY‐DASH repairs ssDNA. On the other hand, cryptochromes, which function either in a blue light‐dependent or light‐independent manner to regulate various processes such as circadian entrainment in insects, growth and development in plants and core clock mechanism in mammals.