Myers Kimberley, Somanath Payaningal R, Berryman Mark, Vijayaraghavan Srinivasan
Department of Biological Sciences, Kent State University, Kent, OH 44242, USA.
FEBS Lett. 2004 May 21;566(1-3):136-40. doi: 10.1016/j.febslet.2004.04.017.
We have identified for the first time the presence of chloride intracellular channel (CLIC) proteins in bovine epididymal spermatozoa. CLIC1 was discovered during microsequencing of proteins that co-purified with protein phosphatase 1, PP1gamma2, in sperm extracts. In addition to CLIC1, Western blot showed that two additional CLIC family members, CLIC4 and CLIC5, are also present in spermatozoa. CLIC fusion proteins, GST-CLIC1, GST-CLIC4 and GST-CLIC5, were all able to bind to PP1gamma2 in sperm extracts during pull-down assays. Immunofluorescence microscopy revealed that each of the three isoforms occupies a distinct location within the cell. Given that PP1gamma2 is a key enzyme regulating sperm motility, PP1gamma2-binding proteins, such as the CLIC proteins, are likely to play significant roles in sperm function.
我们首次在牛附睾精子中鉴定出氯离子细胞内通道（CLIC）蛋白的存在。在对精子提取物中与蛋白磷酸酶1（PP1γ2）共纯化的蛋白质进行微量测序时发现了CLIC1。除CLIC1外，蛋白质印迹法显示另外两个CLIC家族成员CLIC4和CLIC5也存在于精子中。在下拉试验中，CLIC融合蛋白GST-CLIC1、GST-CLIC4和GST-CLIC5都能够与精子提取物中的PP1γ2结合。免疫荧光显微镜检查显示，这三种同工型中的每一种在细胞内都占据一个独特的位置。鉴于PP1γ2是调节精子活力的关键酶，与PP1γ2结合的蛋白质，如CLIC蛋白，可能在精子功能中发挥重要作用。
