四、细胞核转录因子的分离和鉴定

　　四、细胞核转录因子的分离和鉴定

　　信号转导的结果是细胞核内一些转录因子同DNA上某些特定的序列结合，调节转录活性和基因的表达水平。因而分离鉴定细胞内核转录因子在信号转导研究中具有独特的意义。根据核转录因子可与一些特定的核甘酸序列结合的特点，将其特定的核苷序列标记上同位素，来鉴定信号转导中的核转录因子。核转录因子具有一些特征性的结构域，即亮氨酸拉链（lucine zipper）、锌指结构（zinc finger）和螺旋-转角-螺旋（helix-turn-helix）结构。并且受用足迹法（foot printing）分析新发现核转录因子结合DNA的位置和核甘酸序列。

　　随着分子生物学核技术的发展，信号转导研究取得很大进展。采用基因克隆技术发现了越来越多的信号蛋白分子；嵌合分子的构建及基因转染等技术的应用为细胞因子的信号转导研究提供了有效的手段；点突变、肽竞争等技术使信号蛋白中某些功能区的作用的研究变得更为精确。

（夏海滨 金伯泉）

参考文献

　　1.Abraham N, et al. Activation of p^56l ckthrough mutation of a regulatory carboxylterminal tyrosine residuse intact sites of autophosphorylation and myristylation.

　　2.Altman A, et al. Molecular events mediating T cell activation. Adv Immun,1990;48:277.

　　3.Andrea M, et al. The PH domain: a common piece in the structural patchwork of signalling protein.TIBS,1993;18:343.

　　4.Barber EK, et al. The CD4 and CD8 antigens are coupled to a protein tyrosine kinase (p56^lck) that phosphorylates the CD3 complex.Proc Natl　Acad. Sci USA,1989;86:3277.

　　5.Baixeras　E, et al. Signal transduction pathways involved in B cell induction. Immunological Reviews,1993;132:5.

　　6.Blumberg RS, et al. Structure of the T cell antigen receptor: Evidence for two CD3 subunits in the T cell receptor CD3 complex. Proc Natl Acal Sci USA,1990;87:7220.

　　7.Burgess EK, et al. Biochemical identification of a direct physical interaction between the CD4:p56^lck and Ti(TCR)/CD3complexes. Eur J Immunol,1991;21:1663.

　　8.Carel JM, et al. Dual antigen recognition by Bcells. Immuol Today,1993;14(1).

　　9.Christopher ER, et al.CD4,CD8 and the TCR-CD3complex: a novel class of protein-tyrosine kinase receptor. Immunol Today,1990;11(11):400.

　　10.Cooke MP, et al. Expression of a novel form of the fyn protooncogene in hematopoietic cells. New Biol,1989;1:66.

　　11.Damjanivich S, et al. Transmembrane signalling in cells. Immunol Today,1992;13(8):12.

　　12.Glaichenhaus N, et al. Requirement for association of p56^lckwith CD4 in antigen specific signal transduction in T cells.Cell,1991;64:511.

　　13.Gold M, et al. Both phosphatidylinositol 3-kinase and phosphatidylinositol 4-ki-nase products are increased by antigen receptor signaling　in B cells. J Immunol,1994;152:42.

　　14.Irving BA, et al. The cytoplasmic domain of the T cell receptor chain is sufficient to coupled to receptor-associated signal transduction pathways.Cell,1991;64:891.

　　15.Julius M, et al. Distinct role for CD4 and CD8 as co-receptors in antigen receptor signalling. Immunol Today,1993;14(4):17.

　　16.Kishomoto T, et al. Cytokine signal transduction.Cell,1994;76:253.

　　17.Koch C, et al.CH-2 and SH-3 domains: elements that control interactions of cytoplasmic signaling proteins.Science,1991;252:668.

　　18.Kwang-myong K, et al. Signaling function of the B cell antigen receptors. Immunological Revievs,1993;132:125.

　　19.Noah Isakov. Tyrosine phosphorylation and dephosphorylation in T lymphocyte activation. Molecular Immunolgy,1993;30(1):197.

　　20.Pawson T, et al.SH-2 and SH-3 domains: from structure to function.Cell,1992;71:359.

　　21.Philippe CH, et al. An immunologist's look at Rho and Rab GTP binding proteins. Immunology Today.1993;14(9):440.

　　22.Takeshita T, et al. Cloning of the γ chain of the human IL-2receptor.Science,1992;257:379.

　　23.Mustelin T and Burn P. Regulation of src family tyrosine kinase in lymphocytes.TIBS,1993;18:215.