Domain- and sequence-specific phosphorylation of vimentin induces disassembly of the filament structure

Abstract

We reported that stoichiometric phosphorylation by either cAMP-dependent protein kinase or protein kinase C induces disassembly of vimentin filaments [Inagaki, M., Nishi, Y., Nishizawa, K., Matsuyama, M., & Sato, C. (1987) Nature 328, 649-652; Inagaki, M., Gonda, Y., Matsuyama, M., Nishizawa, K., Nishi, Y., & Sato, C. (1988) J. Biol. Chem. 263, 5970-5978]. In the present work, we attempted to identify the sites of vimentin phosphorylated by each protein kinase. Sequential analysis of the purified phosphopeptides, together with the known primary sequence, revealed that Ser-8, Ser-9, Ser-20, Ser-25, Ser-33, and Ser-41 were specifically phosphorylated by protein kinase C, whereas Ser-46 was phosphorylated preferentially by cAMP-dependent protein kinase. Both kinases reacted with Ser-6, Ser-24, Ser-38, Ser-50, and Ser-65. Specific phosphorylation sites for protein kinase C are mostly located close to the amino-terminal side of arginine while those for cAMP-dependent protein kinase are located close to the carboxyl-terminal side of arginine. The phosphorylation sites exclusively occur in the amino-terminal non-alpha-helical head domain, particularly at the beta-turn region. These results provide clues to the molecular mechanisms of phosphorylation-dependent disassembly of vimentin filaments.

The Intermediate Filament Protein Vimentin Is a New Target for Epigallocatechin Gallate

“…IFs are essential for structure and mechanical integration of the cellular space and a variety of cellular functions such as mitosis, locomotion, and organizational cell architecture, and vimentin is readily phosphorylated by numerous protein kinases, thereby regulating their function (15)(16)(17). The proteolytic derivatives indicate that the aminoterminal domain, but not the carboxyl-terminal domain, has a direct effect on filament stability and polymerization (18). We used the Swiss-Prot program and a program from the National Genomic Information center to search the MALDI-TOF data base for peptides important in binding with EGCG.…”

Proteomic analysis of the effect of iptakalim on human pulmonary arterial smooth muscle cell proliferation

“…Various cellular processes, including signal transduction, cytoskeletal stability, and cell apoptosis, have been associated with alterations of IFs [29] . Vimentin contains several phosphorylation sites [31] and is a substrate for many protein kinases, such as p34 Cdc2 kinase [32] , PKA, PKC [33] , Ca 2+ -calmodulin-dependent protein kinase II [34] , p21-activated kinase [35] and MAPK-activated protein kinase-2 [36] . The proteolytic degradation of vimentin is a component of the executive process of cell apoptosis [37] .…”

Induction of adipose conversion in 3T3‐L1 cells is associated with an early phosphorylation of a protein partly homologous with mouse vimentin

“…An RKXXS protein kinase A motif which could serve as a potential site for phosphorylation [23] may indeed be identified within the 14 kDa peptide 1 (a.a. 221-225). It should be noted however, that all previously reported protein kinase A-phosphorylation sites of vimentin are rather located within the stretch of the first 70 amino acids starting at the blocked NH,-terminus while the RKXXS site at a.a. 221-225 has not been previously reported to be phosphorylated by protein kinase A in vitro [24] or in vivo [25]. Alternatively, the radioactivity co-electrophoresed with peptide 1 following V8 cleavage could perhaps be accounted for by an additional 14 kDa peptide derived from the first N 140 a.a. of vimentin and which co-electrophoresed with a non-labelled 14 kDa peptide 1.…”