000 02940nam a2200349Ia 4500
003 MX-MdCICY
005 20250625160143.0
040 _cCICY
090 _aB-16013
245 1 0 _aA PtdIns4,5P2-regulated nuclear poly(A)polymerase controls expression of select mRNAs
490 0 _vNature, 451(7181), p.1013-1017, 2008
520 3 _aPhosphoinositides are a family of lipid signalling molecules that regulate many cellular functions in eukaryotes. Phosphatidylinositol-4,5-bisphosphate (PtdIns4,5P2), the central component in the phosphoinositide signalling circuitry, is generated primarily by type I phosphatidylinositol 4-phosphate 5-kinases (PIPKIa, PIPKIß and PIPKI?). In addition to functions in the cytosol, phosphoinositides are present in the nucleus, where they modulate several functions; however, the mechanism by which they directly regulate nuclear functions remains unknown. PIPKIs regulate cellular functions through interactions with protein partners, often PtdIns4,5P2 effectors, that target PIPKIs to discrete subcellular compartments, resulting in the spatial and temporal generation of PtdIns4,5P2 required for the regulation of specific signalling pathways. Therefore, to determine roles for nuclear PtdIns4,5P2 we set out to identify proteins that interacted with the nuclear PIPK, PIPKIa. Here we show that PIPKIa co-localizes at nuclear speckles and interacts with a newly identified non-canonical poly(A)polymerase, which we have termed Star-PAP (nuclear speckle targeted PIPKIa regulated-poly(A)polymerase)and that the activity of Star-PAP can be specifically regulated by PtdIns4,5P2. Star-PAP and PIPKIa function together in a complex to control the expression of select mRNAs, including the transcript encoding the key cytoprotective enzyme haem oxygenase-1 (refs 8, 9)and other oxidative stress response genes by regulating the 3'-end formation of their mRNAs. Taken together, the data demonstrate a model by which phosphoinositide signalling works in tandem with complement pathways to regulate the activity of Star-PAP and the subsequent biosynthesis of its target mRNA. The results reveal a mechanism for the integration of nuclear phosphoinositide signals and a method for regulating gene expression. ©2008 Nature Publishing Group.
650 1 4 _aENZYME
650 1 4 _aEUKARYOTE
650 1 4 _aGENE EXPRESSION
650 1 4 _aLIPID
650 1 4 _aMETHODOLOGY
650 1 4 _aMODEL
650 1 4 _aMOLECULAR ANALYSIS
650 1 4 _aPROTEIN
650 1 4 _aRNA
700 1 2 _aMellman, D.L.
700 1 2 _aGonzales, M.L.
700 1 2 _aSong, C.
700 1 2 _aBarlow, C.A.
700 1 2 _aWang, P.
700 1 2 _aKendziorski, C.
700 1 2 _aAnderson, R.A.
856 4 0 _uhttps://drive.google.com/file/d/1JxbXTwJFZzvzh9jwaeQEUGNlZp72b4TS/view?usp=drivesdk
_zPara ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx
942 _2Loc
_cREF1
008 250602s9999 xx |||||s2 |||| ||und|d
999 _c50189
_d50189