Volume 15, No 7, Jul 2005

ISSN: 1001-0602 
EISSN: 1748-7838 2018 
impact factor 17.848* 
(Clarivate Analytics, 2019)

Volume 15 Issue 7, July 2005: 495-503

ORIGINAL ARTICLES

Protein kinase clk/STY is differentially regulated during erythroleukemia cell differentiation: a bias toward the skipped splice variant characterizes postcommitment stages

Ana GARCÍA-SACRISTÁN^¶, María J. FERNÁNDEZ-NESTOSA, Pablo HERNÁNDEZ, Jorge B.SCHVARTZMAN, Dora B. KRIMER^*

Department of Cell and Developmental Biology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, Madrid 28040, Spain
^¶Present address: Institute of Molecular Medicine, 1649-028, Lisbon Medical School, Lisbon Portugal Correspondence: Dora B. KRIMER(dbkrimer@cib.csic.es)

Clk/STY is a LAMMER protein kinase capable to phosphorylate serine/arginine-rich (SR) proteins that modulate pre-mRNA splicing. Clk/STY alternative splicing generates transcripts encoding a full-length kinase and a truncated catalytically inactive protein. Here we showed that clk/STY, as well as other members of the family (e.g. clk2, clk3 and clk4), are up-regulated during HMBA-induced erythroleukemia cell differentiation. mRNAs coding for the full-length and the truncated forms were responsible for the overall increased expression. In clk/STY, however, a switch was observed for the ratio of the two alternative spliced products. In undifferentiated cells the full-length transcript was more abundant whereas the transcript encoding for the truncated form predominated at latter stages of differentiation. Surprisingly, overexpression of clk/STY did not alter the splicing switch upon differentiation in MEL cells. These results suggest that clk/STY might contribute to control erythroid differentiation by a mechanism that implicates a balance between these two isoforms.

clk/STY, LAMMER kinase, alternative splicing, erythroleukemia cells.

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