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YAO, XiaoQiang
Associate Professor
B.S. (1982)Hangzhou University
M.S. (1985) Chinese Academy of Science
Ph.D.(1992) State University of New York at Buffalo
Research Interests:
Molecular physiology of ion channel
Research Interests: Molecular physiology of ion channel
Ion channels are essential for a variety of fundamental cell processes. The primary focus of our laboratory is to study Ca2+-permeable channels in vascular endothelial cells and in central nervous system.
1. A protein kinase G-sensitive Ca2+-permeable channel in vascular endothelial cells
We are the first to identify this PKG-sensitive cation channel in vascular endothelial cell. Our research demonstrates that this channel is the primary pathway mediating blood flow-induced Ca2+ influx. It is also the predominant pathway mediating "store-operated Ca2+ influx" in vascular endothelial cells. It is likely that this channel is the target site of a negative feedback mechanism through which endothelial cytosolic Ca2+, endothelial NO and endothelial EDHF, can be regulated. We are currently in the process of isolating this important Ca2+-permeable channel.
2. A cyclic nucleotide-gated nonselective cation channel.This channel is expressed in a variety of tissues. It plays an important role in visual signal transduction and in long-term memory. It also participates in the control of vascular tone. We are currently in the process of isolating new isoforms of this cyclic nucleotide-gated channel. The purpose of this study is to isolate specific channels involved in the long-term memory and in the vascular regulation.
3. A voltage-gated potassium channel (Kv1.3).Kvl.3 is the dominant K+ channel in T lymphocytes. It plays an important role in the activation and proliferation of T lymphocytes. Kvl.3 is also required for the volume regulation and membrane potential control in T lymphocytes. We have recently isolated a mutated form of Kv1.3. Moreover, we have identifies a few amino acids in Kv1.3 which are critically required for the activation and proliferation of T lymphocytes. Currently we are studying the molecular mechanism of K channel involvement in T lymphocyte activation. The purpose of the study is to provide some new insights into the mechanism of T-cell activation, and more importantly, to help develop new strategies for treatment of graft rejection and immune diseases.
Various techniques are currently used to study the molecular physiology of ion channels. These includes confocal Ca2+ image system, oocyte clamp, patch clamp, molecular cloning, in vitro transcription, DNA sequencing, RT -PCR, etc
Selected Publications:
* X Yao, HY Kwan, NWK Chan, Y Huang (2000) A protein kinase G-sensitive channel mediates flow-induced Ca2+ entry in endothelial cells. FASEB Journal. 14: 932-938.
* X Yao, WM Liu, SL Tian, H Rafi, AS Segal, GV Desir (2000) Close association of the amino terminus of Kv1.3 with the pore region. Journal of Biological Chemistry. 275: 10859-10863.
* HY Kwan, Y Huang, X Yao (2000) Store-operated Ca++ entry in vascular endothelial cells is inhibited by cGMP via a protein kinase G-dependent mechanism. Journal of Biological Chemistry. 275:6758-6773.
* X Yao, PS Leung, Kwan HY, TP Wong, MW Fong (1999) Rod-type cyclic nucleotide-gated cation channel is expressed in vascular endothelium and vascular smooth muscle cells. Cardiovascular Research. 41:282-290.
* X Yao, A Chang, E Boulpaep, AS Segal, and GV Desir (1996) Molecular cloning of a glibenclamide-sensitive voltage-gated potassium channel preferentially expressed in rabbit kidney medulla. Journal of Clinical Investigtion. 97:2525-2533.*X Yao, AS Segal, P Welling, X Zhang, D Engel, E Boulpaep and GV Desir (1995) Primary structure and functional expression of a cGMP-gated potassium channel. Proc. Natl. Acad. Sci. USA. 92:11711-11715.
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