Montmayeur J P, Borrelli E
Laboratoire de Génétique Moléculaire des Eucaryotes, CNRS, INSERM U184, Faculté de Médecine, Strasbourg, France.
Science. 1994 Jan 7;263(5143):95-8. doi: 10.1126/science.8272874.
Heterotrimeric guanosine triphosphate (GTP)-binding proteins (G proteins) may participate in membrane traffic events. A complementary DNA (cDNA) was isolated from a mouse pituitary cDNA library that corresponded to an alternatively spliced form of the gene encoding the G protein alpha subunit G alpha i2. The cDNA was identical to that encoding G alpha i2 except that the region encoding for the carboxyl-terminal 24 amino acids was replaced by a longer region encoding 35 amino acids that have no sequence similarity with G alpha i2 or other members of the G protein family. This alternative spliced product and the corresponding protein (sGi2) were present in several tissues. Specific antibodies revealed that sGi2 was localized in the Golgi apparatus, suggesting a role in membrane transport. Thus, alternative splicing may generate from a single gene two G protein alpha subunits with differential cellular localization and function.
异三聚体鸟苷三磷酸（GTP）结合蛋白（G蛋白）可能参与膜转运事件。从小鼠垂体cDNA文库中分离出一个互补DNA（cDNA），它对应于编码G蛋白α亚基Gαi2的基因的一种可变剪接形式。该cDNA与编码Gαi2的cDNA相同，只是编码羧基末端24个氨基酸的区域被一个更长的区域所取代，该区域编码35个氨基酸，与Gαi2或G蛋白家族的其他成员没有序列相似性。这种可变剪接产物和相应的蛋白质（sGi2）存在于几种组织中。特异性抗体显示sGi2定位于高尔基体，提示其在膜转运中发挥作用。因此，可变剪接可能从单个基因产生两个具有不同细胞定位和功能的G蛋白α亚基。
