4 VARIANT CHICKEN ERYTHROID AE1 ANION-EXCHANGERS - ROLE OF THE ALTERNATIVE N-TERMINAL SEQUENCES IN INTRACELLULAR TARGETING IN TRANSFECTED HUMAN ERYTHROLEUKEMIA-CELLS
4 VARIANT CHICKEN ERYTHROID AE1 ANION-EXCHANGERS - ROLE OF THE ALTERNATIVE N-TERMINAL SEQUENCES IN INTRACELLULAR TARGETING IN TRANSFECTED HUMAN ERYTHROLEUKEMIA-CELLS
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DOI：
10.1074/jbc.270.34.19752
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发表时间：
1995-08-25
影响因子：
4.8
通讯作者：
COX, JV
中科院分区：
文献类型：
--
作者：
COX, KH;ADAIRKIRK, TL;COX, JV
四种变体 AE1 阴离子交换剂在鸡类红细胞中表达，其预测分子量分别为 99、102、104 和 108 kDa。这些变体多肽的序列仅在其细胞质结构域的 N 末端不同。分子分析表明，源自红细胞特异性启动子 P1 和 P2 的转录物编码所有四种 AE1 阴离子交换变体。然而，定量 RNase 保护分析表明，源自 P1 启动子的转录本比源自 P2 启动子的转录本更为普遍，逆转录酶聚合酶链反应研究表明，源自 AE1 基因的转录本在原始和定型红系细胞中均存在广泛的多样性，使用人红白血病细胞的瞬时转染分析研究了这些变异交换子 N 末端替代序列的功能意义。红系AE1变体在这些细胞中被分选到不同的膜区室，与99-kDa和与102-kDa类似的变体主要被分选到质膜，而与108-kDa类似的变体保留在核周区室中。这些结果表明，这些多肽的替代N端细胞质序列可以充当信号，将这些变体转运蛋白引导至细胞内的不同膜区室。
Four variant AE1 anion exchangers with predicted molecular masses of similar to 99, similar to 102, similar to 104, and similar to 108 kDa are expressed in chicken erythroid cells. These variant polypeptides differ in sequence only at the N terminus of their cytoplasmic domains, Molecular analyses have shown that transcripts derived from both of the erythroid-specific promoters, P1 and P2, encode all four of these AE1 anion exchanger variants. However, quantitative RNase protection analyses have shown that the transcripts derived from the P1 promoter are much more prevalent than those derived from the P2 promoter, Reverse transcriptase polymerase chain reaction studies have indicated that the extensive diversity in the transcripts derived from the AE1 gene occurs both in primitive and definitive lineage erythroid cells, Transient transfection analyses using human erythroleukemia cells have investigated the functional significance of the alternative sequences at the N terminus of these variant exchangers, These studies have shown that the erythroid AE1 variants are sorted to different membrane compartments in these cells, The similar to 99- and similar to 102-kDa variants are primarily sorted to the plasma membrane, whereas the similar to 108-kDa variant is retained in a perinuclear compartment. These results suggest that the alternative N-terminal cytoplasmic sequences of these polypeptides may serve as signals to direct these variant transporters to different membrane compartments within cells.