- The Arabidopsis inositol 1,3,4-trisphosphate 5/6 kinase, AtItpk-1, is involved in plant photomorphogenesis under red light conditions, possibly via interaction with COP9 signalosome. Qin, Z.X., Chen, Q.J., Tong, Z., Wang, X.C. Plant Physiol. Biochem. (2005)