Rideau Alexis P, Gooding Clare, Simpson Peter J, Monie Tom P, Lorenz Mike, Hüttelmaier Stefan, Singer Robert H, Matthews Stephen, Curry Stephen, Smith Christopher W J
Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, CB2 1GA, UK.
Nat Struct Mol Biol. 2006 Sep;13(9):839-48. doi: 10.1038/nsmb1137. Epub 2006 Aug 27.
Polypyrimidine tract-binding protein (PTB) is a regulatory splicing repressor. Raver1 acts as a PTB corepressor for splicing of alpha-tropomyosin (Tpm1) exon 3. Here we define a minimal region of Raver1 that acts as a repressor domain when recruited to RNA. A conserved [S/G][I/L]LGxxP motif is essential for splicing repressor activity and sufficient for interaction with PTB. An adjacent proline-rich region is also essential for repressor activity but not for PTB interaction. NMR analysis shows that LLGxxP peptides interact with a hydrophobic groove on the dorsal surface of the RRM2 domain of PTB, which constitutes part of the minimal repressor region of PTB. The requirement for the PTB-Raver1 interaction that we have characterized may serve to bring the additional repressor regions of both proteins into a configuration that allows them to synergistically effect exon skipping.
聚嘧啶序列结合蛋白（PTB）是一种调控性剪接抑制因子。Raver1作为PTB的共抑制因子，参与α-原肌球蛋白（Tpm1）外显子3的剪接。在此，我们确定了Raver1的一个最小区域，该区域在被招募到RNA时可作为抑制结构域。一个保守的[S/G][I/L]LGxxP基序对于剪接抑制活性至关重要，并且足以与PTB相互作用。相邻的富含脯氨酸区域对于抑制活性也必不可少，但对于与PTB的相互作用并非必需。核磁共振分析表明，LLGxxP肽与PTB的RRM2结构域背表面的疏水凹槽相互作用，该凹槽构成了PTB最小抑制区域的一部分。我们所描述的PTB与Raver1相互作用的要求，可能有助于使两种蛋白质的其他抑制区域形成一种构型，从而使它们能够协同作用导致外显子跳跃。
