Mitotic Phosphorylation of Golgi Reassembly Stacking Protein 55 by Mitogen-activated Protein Kinase ERK2

AUTOR(ES)

Jesch, Stephen A.

FONTE

The American Society for Cell Biology

RESUMO

The role of the mitogen-activated protein kinase kinase (MKK)/extracellular-activated protein kinase (ERK) pathway in mitotic Golgi disassembly is controversial, in part because Golgi-localized targets have not been identified. We observed that Golgi reassembly stacking protein 55 (GRASP55) was phosphorylated in mitotic cells and extracts, generating a mitosis-specific phospho-epitope recognized by the MPM2 mAb. This phosphorylation was prevented by mutation of ERK consensus sites in GRASP55. GRASP55 mitotic phosphorylation was significantly reduced, both in vitro and in vivo, by treatment with U0126, a potent and specific inhibitor of MKK and thus ERK activation. Furthermore, ERK2 directly phosphorylated GRASP55 on the same residues that generated the MPM2 phospho-epitope. These results are the first demonstration of GRASP55 mitotic phosphorylation and indicate that the MKK/ERK pathway directly phosphorylates the Golgi during mitosis.

Documentos Relacionados

• Association of ERK2 mitogen-activated protein kinase with human immunodeficiency virus particles.
• MAPKAP kinase-2; a novel protein kinase activated by mitogen-activated protein kinase.
• Activation of Mitogen-activated Protein Kinase (Mitogen-activated Protein Kinase/Extracellular Signal-regulated Kinase) Cascade by Aldosterone
• The mitogen-activated protein (MAP) kinase ERK induces tRNA synthesis by phosphorylating TFIIIB
• MsERK1: a mitogen-activated protein kinase from a flowering plant.