期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2002
卷号：99
期号：22
页码：14572-14577
DOI：10.1073/pnas.222539999
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：This study is aimed at identifying the Na pump isoform composition of human erythroid precursor cells and mature human erythrocytes. We used purified and synchronously growing human erythroid progenitor cells cultured for 7-14 days. RNA was extracted from the progenitor cells on different days and analyzed by RT-PCR. The results showed that only the 1, 3, {beta}2, and {beta}3 subunit isoforms and the {gamma} modulator were present. Northern analysis of the erythroid progenitor cells again showed that {beta}2 but not {beta}1 or 2 isoforms were present. The erythroid cells display a unique {beta} subunit expression profile (called {beta}-profiling) in that they contain the message for the {beta}2 isoform but not {beta}1, whereas leukocytes and platelets are known to have the message for the {beta}1 but not for the {beta}2 isoform. This finding is taken to indicate that our preparations are essentially purely erythroid and free from white cell contamination. Western analysis of these cultured progenitor cells confirmed the presence of 1, 3, (no 2), {beta}2, {beta}3, and {gamma} together now with clear evidence that {beta}1 protein was also present at all stages. Western analysis of the Na pump from mature human erythrocyte ghosts, purified by ouabain column chromatography, has also shown that 1, 3, {beta}1, {beta}2, {beta}3, and {gamma} are present. Thus, the Na pump isoform composition of human erythroid precursor cells and mature erythrocytes contains the 1 and 3 isoforms of the subunit, the {beta}1, {beta}2, and {beta}3 isoforms of the {beta} subunit, and the {gamma} modulator.
