Regulation of the kinase activity of the MIK GCK-like MAP4K by alternative splicing |
| |
Authors: | Enric Castells Pere Puigdomènech Josep M Casacuberta |
| |
Affiliation: | (1) Departament de Genètica Molecular, Laboratori de Genètica Molecular Vegetal CSIC-IRTA, Institut de Biologia Molecular de Barcelona (IBMB-CSIC), Jordi Girona 18, 08034 Barcelona, Spain |
| |
Abstract: | Alternative splicing of introns is essential to ensure the complexity of mammalian genome functions. In particular, the generation
of a high number of different isoforms by alternative splicing is an important characteristic of genes coding for signalling
proteins such as mitogen activated protein kinases (MAPKs). This is thought to allow these proteins to transduce multiple
stimuli in a highly regulated manner. Plant genes are also subjected to alternative splicing. Nevertheless, clear examples
of the functional consequences of this phenomenon are still scarce in plants. MIK is a maize gene coding for a GCK-like MAP4K that can be activated by interaction with maize atypical receptor kinase (MARK),
an atypical receptor kinase. Here we show that MIK is subjected to alternative splicing. Expression of MIK leads to, at least, 4 different mature mRNAs that accumulate with particular expression profiles during maize development.
Our results show that the polypeptides encoded by the different MIK mRNAs display different kinase activity and are differentially activated by interaction with the MARK receptor. Two MIK isoforms
display constitutive kinase activity, one isoform is inactive but can be activated by MARK, and the fourth MIK isoform is
inactive and cannot be activated by MARK. Our results constitute a clear example of the biochemical consequences of alternative
splicing in plants. The selective conservation during evolution of the intron–exon structure of the region coding for the
regulator domain of MIK, as well as the maintenance in maize, rice and Arabidopsis of the alternative splicing of some of
these introns, are strong indications of its functional importance. |
| |
Keywords: | Alternative splicing Intron retention MAPK MIK Receptor kinase |
本文献已被 PubMed SpringerLink 等数据库收录! |
|