Abramovich C, Ratovitski E, Lundgren E, Revel M
Department of Molecular Genetics and Virology, Weizmann Institute of Science, Rehovot, Israel.
FEBS Lett. 1994 Feb 7;338(3):295-300. doi: 10.1016/0014-5793(94)80287-4.
Transcripts of the human IFN alpha-receptor (IFNAR) gene, lacking the transmembrane (TM) domain were found in human myeloma U266S cells, in addition to the transmembranal IFNAR cDNA. Two different cDNAs encoding such soluble IFNAR forms were identified. Form 1 has a deletion causing a frameshift toward the end of the extracellular (EC) domain predicting a tail of 7 amino acids. Form 2 has two in-frame deletions and conserves most of the intracytoplasmatic domain of IFNAR. The transcripts for the two soluble forms are still found in U266R cells which have lost the transmembranal IFNAR transcript. Human cells seem to have independent mechanisms to synthesize soluble IFN receptors, which may act as competitors outside the cells or carry IFN-mediated functions inside the cell.
除了跨膜的IFNAR cDNA外，在人骨髓瘤U266S细胞中还发现了缺少跨膜（TM）结构域的人IFNα受体（IFNAR）基因转录本。鉴定出两种编码这种可溶性IFNAR形式的不同cDNA。形式1有一个缺失，导致向细胞外（EC）结构域末端的移码，预测有一个7个氨基酸的尾巴。形式2有两个框内缺失，并保留了IFNAR的大部分胞质内结构域。两种可溶性形式的转录本仍可在已失去跨膜IFNAR转录本的U266R细胞中发现。人类细胞似乎有独立的机制来合成可溶性IFN受体，这些受体可能在细胞外作为竞争者起作用，或者在细胞内发挥IFN介导的功能。
