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Proteomic‐based analysis of nuclear signaling: PLCβ 1 affects the expression of the splicing factor SRp20 in Friend erythroleukemia cells
Author(s) -
Bavelloni Alberto,
Faenza Irene,
Cioffi Gabriella,
Piazzi Manuela,
Parisi Daniela,
Matic Ivan,
Maraldi Nadir M.,
Cocco Lucio
Publication year - 2006
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.200600318
Subject(s) - alternative splicing , splicing factor , microbiology and biotechnology , effector , biology , rna splicing , nuclear protein , gene isoform , transcription factor , genetics , gene , rna
Abstract An extensive body of evidence links inositide‐specific phospholipase C (PLC) to the nucleus and the main isoform located in the nucleus is PLCβ 1 . Constitutive overexpression of nuclear PLCβ 1 has been previously shown to inhibit Friend erythroleukemia cells differentiation and to induce cell cycle progression targeting cyclin D3. The aim of this study was to identify new proteins regulated by PLCβ 1 overexpression, given the role exerted by its signaling in the nucleus during cell growth and differentiation. To identify novel downstream effectors of nuclear PLCβ 1 ‐dependent signaling in Friend erythroleukemia cells, we performed the high‐resolution 2‐DE‐based proteomic analysis. Using a proteomic approach we found that SRp20, a member of the highly conserved SR family of splicing regulators, was down‐regulated in cells overexpressing nuclear PLCβ 1 as compared with wild‐type cells. Reduction in SRp20 was confirmed by 2‐D Western blotting. Moreover, we have shown that nuclear PLCβ 1 is bound to the SRp20 splicing factor. Indeed, by immunoprecipitation and subcellular fractioning, we have demonstrated that endogenous PLCβ 1 and SRp20 physically interact in the nucleus. Here we show the existence of a PLCβ 1 ‐specific target, the splicing factor SRp20, whose expression is specifically down‐regulated by the nuclear signaling evoked by PLCβ 1 .