Identifizierung von Cyclin L2 und des Spleißfaktors SF3B1 als Substrate der Proteinkinase DYRK1A

The protein kinase DYRK1A is supposed to play an important role in the development of the central nervous system. However the exact role of the kinase in the cell is largely unknown. It was the aim of this study to identify substrates to get insights about the cellular function of the kinase. By phosphorylation of the proteins of a cDNA expression library with DYRK1A, eight in vitro substrates were identified. Two of them, cyclin L2 and SF3B1, were chosen for further investigations. Cyclin L2 combines a cyclin domain with an arginine-serine-rich (RS)-domain and was extensively characterised in this work. Alternatively spliced transcripts were identified and their expression in different tissues was analysed. The results demonstrate that the RS-domain of cyclin L2 is responsible for the interaction with the splicing factor ASF2 and the localisation in nuclear speckles, which are supposed to be storage compartments of splicing factors. By the production of a specific antibody, the protein could be detected in mouse testis. DYRK1A phosphorylates cyclin L2 both in vitro and in COS-7 cells. SF3B1 is a central component of the splicosome and is phosphorylated during the splicing process. CDK2 in combination with the regulatory subunit cyclin E has been proposed as a candidate responsible for this phosphorylation. Kinetic analysis demonstrates that SF3B1 is a high affinity in vitro substrate of both DYRK1A and CDK2/CyclinE. But the data obtained in this work suggest that the main part of the phosphorylation in COS-7 cells is catalysed by DYRK1A and not CDK2. Thus, DYRK1A is a promising candidate for the regulatory phosphorylation described in the literature. The substrates identified in this work suggest a regulatory function of DYRK1A in splicing processes.

Grantor dc:publisher

Publikationsserver der RWTH Aachen University

Year dc:date

2004

Author dc:creator

• de Graaf, Katrin

Contributors dc:contributor

• Becker, Walter

• info:eu-repo/classification/ddc/570
• Proteinkinasen
• Cyclin-abhängige Kinasen
• Enzymsubstrat
• Cycline
• Spleißfaktor
• Biowissenschaften, Biologie
• DYRK1A
• SF3B1
• Cyclin L2
• Spleißen

Statement dc:rights

• info:eu-repo/semantics/openAccess

Language dc:language

ger

Identifier

https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-123590%22

OAI identifier oai:identifier

oai:publications.rwth-aachen.de:61989