Xyloketal B, a marine compound, acts on a network of molecular proteins and regulates the activity and expression of rat cytochrome P450 3a: a bioinformatic and animal study

Su, Junhui; Chang, Cui; Xiang, Qi; Zhou, Zhi-Wei; Luo, Rong; Yang, Lun; He, Zhi-Xu; Yang, Hongtu; Li, Jianan; Bei, Yu; Xu, Jinmei; Zhang, Minjing; Zhang, Qihao; Su, Zhijian; Huang, Yadong; Pang, Jiyan; Zhou, Shu-Feng

Tyrosine kinase plays an essential role in the selection and maturation of developing T-cells in the thymus and in mature T-cell function. It is constitutively associated with the cytoplasmic portions of the CD4 and CD8 surface receptors and plays a key role in TCR-linked signal transduction pathways. Association of the TCR with a peptide antigen-bound MHC complex facilitates the interaction of CD4 and CD8 with MHC class II and class I molecules, respectively, and thereby recruits the associated LCK to the vicinity of the TCR/CD3 complex. LCK then phosphorylates tyrosine residues within the immune receptor tyrosine-based activation motifs in the cytoplasmic tails of the TCR-γ chains and CD3 subunits, initiating the TCR/CD3 signaling pathway. In addition, it contributes to signaling by other receptor molecules. It associates directly with the cytoplasmic tail of CD2, and upon engagement of the CD2 molecule, LCK undergoes hyperphosphorylation and activation. It also plays a role in the IL2 receptor-linked signaling pathway that controls the T-cell proliferative response. Binding of IL-2 to its receptor results in increased activity of LCK. Is expressed at all stages of thymocyte development and is required for regulation of maturation events that are governed by both pre-TCR and mature α/β-TCR.