Stoss Oliver, Novoyatleva Tatyana, Gencheva Marieta, Olbrich Manuela, Benderska Natalya, Stamm Stefan
Klinikum Kassel, Pathology, Mönchebergstr. 41-43, D-34125 Kassel, Germany.
Mol Cell Neurosci. 2004 Sep;27(1):8-21. doi: 10.1016/j.mcn.2004.04.011.
The Sam68-like mammalian protein SLM-1 is a member of the STAR protein family and is related to SAM68 and SLM-2. Here, we demonstrate that rSLM-1 interacts with itself, scaffold-attachment factor B, YT521-B, SAM68, rSLM-2, SRp30c, and hnRNP G. rSLM-1 regulates splice site selection in vivo via a purine-rich enhancer. In contrast to the widely expressed SAM68 and rSLM-2 proteins, rSLM-1 is found primarily in brain and, to a much smaller degree, in testis. In the brain, rSLM-1 and rSLM-2 are predominantly expressed in different neurons. In the hippocampal formation, rSLM-1 is present only in the dentate gyrus, whereas rSLM-2 is found in the pyramidal cells of the CA1, CA3, and CA4 regions. rSLM-1, but not rSLM-2, is phosphorylated by p59(fyn). p59(fyn)-mediated phosphorylation abolishes the ability of rSLM-1 to regulate splice site selection, but has no effect on rSLM-2 activity. This suggests that rSLM-1-positive cells could respond with a change of their splicing pattern to p59(fyn) activation, whereas rSLM-2-positive cells would not be affected. Together, our data indicate that rSLM-1 is a tissue-specific splicing factor whose activity is regulated by tyrosine phosphorylation signals emanating from p59(fyn).
类Sam68的哺乳动物蛋白SLM-1是STAR蛋白家族的成员，与SAM68和SLM-2相关。在此，我们证明重组SLM-1能与自身、支架附着因子B、YT521-B、SAM68、重组SLM-2、SRp30c和hnRNP G相互作用。重组SLM-1在体内通过富含嘌呤的增强子调节剪接位点选择。与广泛表达的SAM68和重组SLM-2蛋白不同，重组SLM-1主要在脑中发现，在睾丸中的表达程度要小得多。在脑中，重组SLM-1和重组SLM-2主要在不同的神经元中表达。在海马结构中，重组SLM-1仅存在于齿状回，而重组SLM-2存在于CA1、CA3和CA4区的锥体细胞中。重组SLM-1可被p59(fyn)磷酸化，而重组SLM-2则不能。p59(fyn)介导的磷酸化消除了重组SLM-1调节剪接位点选择的能力，但对重组SLM-2的活性没有影响。这表明重组SLM-1阳性细胞可能会随着剪接模式的改变对p59(fyn)激活作出反应，而重组SLM-2阳性细胞则不会受到影响。总之，我们的数据表明重组SLM-1是一种组织特异性剪接因子，其活性受p59(fyn)发出的酪氨酸磷酸化信号调节。
