Unknown,Transcriptomics,Genomics,Proteomics

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L-plastin Ser5 phosphorylation via RSKs, downstream effectors of the MAPK/ERK pathway, in (breast) cancer cells (and in vitro)

ABSTRACT: Deregulated cell migration and invasion, which are hallmarks of metastatic cancer cells, are correlated to structural and functional alterations of the actin cytoskeleton associated to a large panel of actin-binding proteins. Among these, the actin-bundling protein L-plastin, initially detected in leukocytes, is ectopically expressed in several solid tumours and is often considered as a metastatic marker. Phosphorylation of L-plastin on residue serine 5 (Ser5) has been shown to activate L-plastin and to be crucial for invasion and metastasis formation. Here, we investigate the signalling pathway leading to L-plastin Ser5 phosphorylation in four breast cancer cell lines. Whole genome microarray analysis comparing cell lines with different invasive capacities and corresponding L-plastin Ser5 phosphorylation levels revealed that genes of the MAPK/ERK pathway are differentially expressed. In line, in vitro kinase assays showed that MAPK/ERK pathway downstream kinases RSK1 and RSK2 are able to directly phosphorylate L-plastin on Ser5. In parallel to a knockdown approach, activation and inhibition studies of signalling molecules of the MAPK/ERK pathway, followed by computational modelling analysis, confirmed that RSK is an important activator of L-plastin in all four studied cell lines. Finally and rounding up our study, RSK knockdown significantly impaired migratory and invasive capacities of a selected invasive cell line, thus consolidating RSK as a promising therapeutic target in certain invasive carcinomas. Altogether, our data provide substantial evidence that the MAPK/ERK pathway is involved in L-plastin Ser5 phosphorylation in breast cancer cells with its downstream kinases RSK1 and RSK2 being able to directly phosphorylate L-plastin on Ser5.

ORGANISM(S): Homo sapiens

SUBMITTER: Muller Arnaud

PROVIDER: E-MTAB-3487 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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L-plastin Ser5 phosphorylation via RSKs, downstream effectors of the MAPK/ERK pathway, in (breast) cancer cells (and in vitro)

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