Comparison of transport properties of the reduced folate carrier and folate receptor in murine L1210 leukemia cells.
Comparison of transport properties of the reduced folate carrier and folate receptor in murine L1210 leukemia cells.
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鼠 L1210 白血病细胞中还原叶酸载体和叶酸受体转运特性的比较。
DOI：
10.1016/0006-2952(95)94097-y
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发表时间：
1995
影响因子：
5.8
通讯作者：
Goldman,ID
中科院分区：
文献类型：
--
作者：
Sierra,EE;Brigle,KE;Spinella,MJ;Goldman,ID
该实验室先前描述了一种L1210小鼠白血病细胞系，其在还原叶酸载体中存在功能缺陷，并且叶酸受体-β（F2-MTXrA）表达增加。该细胞系用于表征叶酸受体-β介导的甲氨蝶呤（MTX）内流，并将其与L1210亲本细胞中还原叶酸载体介导的内流进行比较。0.2 μ M MTX在F2-MTXrA细胞中的内流是L1210细胞的1/3，并且被非常低浓度的叶酸消除。动力学分析表明，叶酸受体-β介导的MTX转运的内流Ktone为还原型叶酸载体的1/3，Vmax为还原型叶酸载体的1/4。代谢抑制剂显著抑制F2-MTXrA细胞内流，但对L1210细胞内流没有影响。甲氨蝶呤流入两种细胞系抑制有机阴离子丙磺舒，磺溴酞，CI-920，但在较小程度上在F2-MTXrA细胞。这些阴离子对F2-MTXrA细胞转运的抑制作用可能归因于它们抑制MTX与叶酸受体的结合。虽然MTX在两种细胞系中的内流不是钠依赖性的，但去除细胞外氯使L1210细胞中的内流增加2倍，同时显著抑制F2-MTXrA细胞中的内流。用羟乙基磺酸盐或NO3 −取代Cl −可部分恢复后者细胞的内流，而SO42 −则具有抑制作用。阴离子增强MTX与叶酸受体-β的结合，羟乙基磺酸盐> SO42 −> Cl −。将缓冲液pH降低至6.2，L1210细胞和F2-MTXrA细胞中MTX流入量分别减少69%和增加260%。数据表明，叶酸受体-β-介导的MTX内流在能量、离子和pH依赖性方面与还原叶酸载体介导的转运具有根本不同的性质。没有证据表明这些过程在功能上有联系。
This laboratory previously described an L1210 murine leukemia cell line with a functional defect in the reduced folate carrier and increased expression of folate receptor-β (F2-MTXrA). This cell line was used to characterize methotrexate (MTX) influx mediated by folate receptor-β and to compare this with influx mediated by the reduced folate carrier in L1210 parental cells. Influx of 0.2 μM MTX in F2-MTXrA cells was one-third that of L1210 cells and was abolished by very low concentrations of folic acid. Kinetic analysis revealed that MTX transport mediated by folate receptor-β exhibited an influx Ktone-third, and an influx Vmaxone-fourth, that of the reduced folate carrier. Metabolic inhibitors markedly suppressed influx in F2-MTXrA cells but had no effect on MTX influx in L1210 cells. MTX influx in both cell lines was inhibited by the organic anions probenecid, sulfobromophthalein, and CI-920, but to a lesser extent in F2-MTXrA cells. The inhibitory effects of these anions on transport in F2-MTXrA cells could be attributed to their inhibition of MTX binding to the folate receptor. Although MTX influx in both cell lines was not sodium dependent, removal of extracellular chloride increased influx 2-fold in L1210 cells while markedly inhibiting influx in F2-MTXrA cells. Substitution of Cl−with isethionate or NO3−partially restored influx in the latter cells, whereas SO42−was inhibitory. Anions enhanced MTX binding to folate receptor-β with isethionate > SO42−> Cl−. Decreasing the buffer pH to 6.2 produced a 69% reduction, and a 260% increase, in MTX influx in L1210 cells and F2-MTXrA cells, respectively. The data indicate that folate receptor-β-mediated MTX influx has properties fundamentally different from transport mediated by the reduced folate carrier in terms of energy, ion, and pH dependence. There was no evidence indicating that these processes are functionally linked.
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影响因子：
11.2
作者：
F. Sirotnak;D. M. Moccio;C. Young
通讯作者：
F. Sirotnak;D. M. Moccio;C. Young
DOI：
10.1016/s0021-9258(18)91984-8
发表时间：
1968-10
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Norman;S. Lichtenstein;Vincent;-T.;Oliverio
通讯作者：
Norman;S. Lichtenstein;Vincent;-T.;Oliverio
培养的人近端小管细胞的叶酸转运和结合。
DOI：
10.1152/ajprenal.1992.263.5.f841
发表时间：
1992
期刊：
The American journal of physiology
影响因子：
--
作者：
McMartin,KE;Morshed,KM;Hazen-Martin,DJ;Sens,DA
通讯作者：
Sens,DA
2,4-二硝基苯酚和其他代谢抑制剂对艾利希腹水肿瘤细胞中甲氨蝶呤的双向载体通量、净运输和细胞内结合的影响。
影响因子：
11.2
作者：
Fry,DW;White,JC;Goldman,ID
通讯作者：
Goldman,ID
L1210 白血病细胞系的膜蛋白发生变化，其甲氨蝶呤-四氢叶酸辅助因子转运载体存在易位缺陷。
DOI：
--
发表时间：
1989
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Schuetz,JD;Westin,EH;Matherly,LH;Pincus,R;Swerdlow,PS;Goldman,ID
通讯作者：
Goldman,ID