TARGETS OF IMMUNOPHILIN-IMMUNOSUPPRESSANT COMPLEXES ARE DISTINCT HIGHLY CONSERVED REGIONS OF CALCINEURIN-A
TARGETS OF IMMUNOPHILIN-IMMUNOSUPPRESSANT COMPLEXES ARE DISTINCT HIGHLY CONSERVED REGIONS OF CALCINEURIN-A
复制标题
DOI：
10.1002/j.1460-2075.1995.tb07277.x
复制
发表时间：
1995-06-15
期刊：
影响因子：
11.4
通讯作者：
HEITMAN, J
中科院分区：
文献类型：
--
作者：
CARDENAS, ME;MUIR, RS;HEITMAN, J
免疫抑制复合物亲环素A-环孢菌素A（CsA）和FKBP 12-FK 506抑制钙调磷酸酶（calcineurin），钙调磷酸酶是一种调节信号转导的异源二聚体钙调蛋白依赖性蛋白磷酸酶。我们鉴定了从CsA-FK 506敏感的酿酒酵母菌株中分离的CsA或FK 506抗性突变体。（T350 K，T350 R，Y377 F）的钙调磷酸酶A催化亚基CMP 1。一个突变，赋予显性FK 506耐药性改变了一个单一的残基（W 430 C）在钙调磷酸酶A催化亚基CMP 2。在体外和体内，CsA抗性钙调磷酸酶突变体结合FKBP 12-FK 506，但对亲环素A-CsA的亲和力降低。当引入CMP 1亚基时，FK 506抗性突变（W388 G）阻断FKBP 12-FK 506的结合，但不阻断亲环素A-CsA的结合。CsA抗性和FK 506抗性钙调磷酸酶A亚基的GO表达赋予对CsA和FK 506的抗性，但不赋予对CsA + FK 506的抗性，双突变钙调磷酸酶A亚基（Y377 F，W388 C CMP 1和Y 419 F，W 430 C CMP 2）赋予对CsA、FK 506和CsA + FK 506的抗性，这些研究将亲环蛋白A-CsA和FKBP 12-FK 506结合靶点鉴定为钙调磷酸酶A的不同的高度保守区域，其与钙调磷酸酶B调节亚基的结合结构域重叠。
The immunosuppressive complexes cyclophilin A-cyclosporin A (CsA) and FKBP12-FK506 inhibit calcineurin, a heterodimeric Ca2+-calmodulin-dependent protein phosphatase that regulates signal transduction, We have characterized CsA- or FK506-resistant mutants isolated from a CsA-FK506-sensitive Saccharomyces cerevisiae strain, Three mutations that confer dominant CsA resistance are single amino acid substitutions (T350K, T350R, Y377F) in the calcineurin A catalytic subunit CMP1. One mutation that confers dominant FK506 resistance alters a single residue (W430C) in the calcineurin A catalytic subunit CMP2. In vitro and in vivo, the CsA-resistant calcineurin mutants bind FKBP12-FK506 but have reduced affinity for cyclophilin A-CsA. When introduced into the CMP1 subunit, the FK506 resistance mutation (W388G) blocks binding by FKBP12-FK506, but not by cyclophilin A-CsA. Go-expression of CsA-resistant and FK506-resistant calcineurin A subunits confers resistance to CsA and to FK506 but not to CsA plus FK506, Double mutant calcineurin A subunits (Y377F, W388C CMP1 and Y419F, W430C CMP2) confer resistance to CsA, to FK506 and to CsA plus FK506, These studies identify cyclophilin A-CsA and FKBP12-FK506 binding targets as distinct, highly conserved regions of calcineurin A that overlap the binding domain for the calcineurin B regulatory subunit.