Cook T, Mesa K, Urrutia R
Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota, USA.
J Neurochem. 1996 Sep;67(3):927-31. doi: 10.1046/j.1471-4159.1996.67030927.x.
Dynamin proteins are members of a recently described family of GTPases involved in receptor-mediated processes. To date, three different dynamin-encoding genes have been identified in mammalian tissues. Dynamin I is expressed only in neurons, whereas dynamin II is ubiquitously expressed. A third isoform, dynamin III, was originally isolated from a rat testis cDNA library and shown to be testis-specific. However, here we report the cloning and characterization of dynamin III from brain and lung, demonstrating a more extended pattern of expression for this isoform. In addition, we have investigated the temporal pattern of expression of these three genes during brain development. We find that both dynamin I and dynamin III mRNA levels are up-regulated during embryogenesis, whereas dynamin II mRNA levels remain unchanged. From these results, we conclude that dynamin III is not a testis-specific isoform and, furthermore, that rat brain expresses three different dynamin-encoding genes that are differentially regulated during development. Therefore, this large isoform diversity of dynamin proteins in brain predicts a significant complexity in the understanding of dynamin-based processes in this tissue.
发动蛋白是最近描述的参与受体介导过程的GTP酶家族成员。迄今为止，在哺乳动物组织中已鉴定出三种不同的发动蛋白编码基因。发动蛋白I仅在神经元中表达，而发动蛋白II则普遍表达。第三种同工型发动蛋白III最初是从大鼠睾丸cDNA文库中分离出来的，显示为睾丸特异性。然而，我们在此报告从脑和肺中克隆和鉴定发动蛋白III，证明该同工型有更广泛的表达模式。此外，我们研究了这三个基因在脑发育过程中的表达时间模式。我们发现发动蛋白I和发动蛋白III的mRNA水平在胚胎发生过程中上调，而发动蛋白II的mRNA水平保持不变。从这些结果，我们得出结论，发动蛋白III不是睾丸特异性同工型，此外，大鼠脑表达三种不同的发动蛋白编码基因，它们在发育过程中受到不同的调节。因此，脑中发动蛋白的这种大的同工型多样性预示着在理解该组织中基于发动蛋白的过程时具有显著的复杂性。
