Identification of the stereospecific hexose transporter from starved and fed chicken embryo fibroblasts.
Identification of the stereospecific hexose transporter from starved and fed chicken embryo fibroblasts.
复制标题
饥饿和喂养鸡胚成纤维细胞中立体特异性己糖转运蛋白的鉴定。
DOI：
10.1073/pnas.79.7.2286
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发表时间：
1982
影响因子：
11.1
通讯作者：
Czech,MP
中科院分区：
文献类型：
--
作者：
Pessin,JE;Tillotson,LG;Yamada,K;Gitomer,W;Carter-Su,C;Mora,R;Isselbacher,KJ;Czech,MP
当D-葡萄糖剥夺24小时，鸡胚成纤维细胞表现出显着增加的己糖转运活性与对照细胞相比。结合饥饿细胞质膜（46 pmol/mg）的[3 H]细胞松弛素B的Scatchard分析表明，与进食细胞质膜（7.5 pmol/mg）相比，增加了6倍。在0.5 μ M [3 H]细胞松弛素B存在下，用高强度UV光照射饥饿细胞质膜导致Mr 52，000和46，000的多肽的共价标记。在相同条件下照射的饲养细胞质膜中，两种多肽都被标记，但水平大大降低。事实上，Mr 52，000多肽的标记几乎检测不到。D-葡萄糖敏感的[3 H]细胞松弛素B共价插入这些膜组件的量增加了11 +/- 2（n = 4）倍饥饿与喂养细胞质膜。在饥饿的细胞质膜中，两种多肽的光亲和标记被D-葡萄糖、3-O-甲基葡萄糖、2-脱氧葡萄糖、细胞松弛素B和细胞松弛素A抑制，但不被D-山梨醇、L-葡萄糖或细胞松弛素E抑制。对Mr 52，000多肽的标记的半最大抑制发生在8 mM D-葡萄糖，而对于Mr 46，000多肽，半最大抑制发生在40 mM D-葡萄糖。它的结论是：（i）两个己糖转运蛋白，一个Mr 46,000和一个Mr 52,000，已确定在鸡胚成纤维细胞和（ii）增加的亲和力标记这些转运蛋白成分细胞饥饿后，可能反映了质膜转运蛋白的数量增加。
When deprived of D-glucose for 24 hr, chicken embryo fibroblasts exhibit a marked increase in hexose transport activity compared with that of control cells. Scatchard analysis of [3H]cytochalasin B binding to starved cell plasma membranes (46 pmol/mg) indicated a six-fold increase compared with fed cell plasma membranes (7.5 pmol/mg). Irradiation of starved cell plasma membranes with high-intensity UV light in the presence of 0.5 microM [3H]cytochalasin B resulted in covalent labeling of polypeptides of Mr 52,000 and 46,000. In fed cell plasma membranes irradiated under the same conditions, both polypeptides were labeled but at greatly decreased levels. In fact, labeling of the Mr 52,000 polypeptide was barely detectable. The amount of D-glucose-sensitive [3H]cytochalasin B covalent insertion into these membrane components was increased 11 +/- 2 (n = 4)-fold in starved versus fed cell plasma membranes. Photoaffinity labeling of both polypeptides in starved cell plasma membranes was inhibited by D-glucose, 3-O-methylglucose, 2-deoxyglucose, cytochalasin B, and cytochalasin A but not by D-sorbitol, L-glucose, or cytochalasin E. Half-maximal inhibition of labeling of the Mr 52,000 polypeptide occurred at 8 mM D-glucose whereas, for the Mr 46,000 polypeptide, half-maximal inhibition occurred at 40 mM D-glucose. It is concluded that (i) two hexose transport proteins, one of Mr 46,000 and one of Mr 52,000, have been identified in chicken embryo fibroblasts and (ii) the increased affinity labeling of these transporter components after cell starvation may reflect increased numbers of transporters in the plasma membrane.