The CNT1 Domain of Arabidopsis CRY1 Alone Is Sufficient to Mediate Blue Light Inhibition of Hypocotyl Elongation

摘要

Dear Editor, Cryptochromes (CRY) are photolyase-like blue light receptors that mediate various light responses in plants and animals.InArabidopsis,there are two homologous cryptochromes,CRY1 and CRY2,which mainly regulate photomorphogenesis and photoperiodic flowering,respectively (Guo et al.,1998;Lin et al.,1998).Cryptochromes are structurally divided into an N-terminal domain related to the photolyase and a C-terminal extension domain (Yang et al.,2000;Cashmore,2003).The C-terminal domains of CRY1 and CRY2 (CCT1 [residues 490-681] and CCT2 [residues 486-612],also known as CCE1 and CCE2) are shown to mediate blue light signaling,whereas the N-terminal domains of CRY1 and CRY2 (CNT1 [residues 1-489] and CNT2 [residues 1-485]) are known to bind chromophores to sense blue light and mediate CRY dimerization (Yang et al.,2000;Brautigam et al.,2004;Sang et al.,2005).