Tölg C, Hofmann M, Herrlich P, Ponta H
Kernforschungszentrum Karlsruhe, Institut für Genetik, Germany.
Nucleic Acids Res. 1993 Mar 11;21(5):1225-9. doi: 10.1093/nar/21.5.1225.
The enormous heterogeneity of the surface protein designated CD44 is in part due to posttranslational modification, and in part due to differential splicing. Alternative splicing occurs within one particular region encoding the extracellular portion of the protein. Comparison of various cDNA clones with different 'inserts' in this variable region with sequences of genomic clones from the mouse has revealed the existence of at least ten exons from which sequences are chosen by alternative splicing. Various combinations of these exons account for the tremendous heterogeneity of CD44 molecules expressed in different tissues, and in progressing tumor cells. The existence of different isoforms of CD44 suggests a broad spectrum of yet unknown physiologic functions.
名为CD44的表面蛋白具有极大的异质性，部分原因是翻译后修饰，部分原因是可变剪接。可变剪接发生在编码该蛋白细胞外部分的一个特定区域内。将该可变区域中具有不同“插入片段”的各种cDNA克隆与来自小鼠的基因组克隆序列进行比较，发现至少有十个外显子，可变剪接从中选择序列。这些外显子的各种组合导致了在不同组织以及进展期肿瘤细胞中表达的CD44分子具有极大的异质性。CD44不同异构体的存在表明其具有一系列尚未明确的生理功能。
