In vitro and in vivo phosphorylation of myelin basic protein by cerebral protein kinase

Nature ◽  
1974 ◽  
Vol 249 (5453) ◽  
pp. 150-151 ◽  
Author(s):  
EISHICHI MIYAMOTO ◽  
SHIRO KAKIUCHI ◽  
YASUO KAKIMOTO
Keyword(s):  
Protein Kinase ◽  
Myelin Basic Protein ◽  
Basic Protein

scholarly journals Saccharomyces cerevisiae Yak1p protein kinase autophosphorylates on tyrosine residues and phosphorylates myelin basic protein on a C-terminal serine residue

2000 ◽  
Vol 348 (2) ◽  
pp. 263-272 ◽  
Author(s):  
Shouki KASSIS ◽  
Tiffany MELHUISH ◽  
Roland S. ANNAN ◽  
Susan L. CHEN ◽  
John C. LEE ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Catalytic Activity ◽  
Protein Kinase ◽  
Myelin Basic Protein ◽  
Basic Protein ◽  
Full Length ◽  
Tandem Ms ◽  
Tyrosine Residues

The serine/threonine protein kinase, Yak1p, functions as a negative regulator of the cell cycle in Saccharomyces cerevisiae, acting downstream of the cAMP-dependent protein kinase. In the present work we report that overexpression of haemagglutinin-tagged full-lengthYak1p and an N-terminally truncated form (residues 148-807) lead to growth arrest in PKA compromised yak1 null yeast cells. Both forms of recombinant Yak1p kinase were catalytically active and preferred myelin basic protein (MBP) as a substrate over several other proteins. Phosphopeptide analysis of bovine MBP by tandem MS revealed two major Yak1p phosphorylation sites, Thr-97 and Ser-164. Peptides containing each site were obtained and tested as Yak1p substrates. Both forms of Yak1p phosphorylated a peptide containing the Ser-164 residue with far more efficient kinetics than MBP. The maximal velocity (Vmax) values of the full-length Yak1p reaction were 110±21 (Ser-164) and 8.7±1.7 (MBP), and those of N-terminally truncated Yak1p were 560.7±74.8 (Ser-164) and 34.4±2.2 (MBP) pmol/min per mg of protein. Although neither form of Yak1p was able to phosphorylate two generic protein tyrosine kinase substrates, both were phosphorylated on tyrosine residues in vivo and underwent tyrosine autophosphorylation when reacted with ATP in vitro. Tandem MS showed that Tyr-530 was phosphorylated both in vivo and in vitro after reaction with ATP. Pre-treatment with protein tyrosine phosphatase 1B removed all of Yak1p phosphotyrosine content and drastically reduced Yak1p activity against exogenous substrates, suggesting that the phosphotyrosine content of the enzyme is essential for its catalytic activity. Although the N-terminally truncated Yak1p was expressed at a lower level than the full-length protein, its catalytic activity and phosphotyrosine content were significantly higher than those of the full-length enzyme. Taken together, our results suggest that Yak1p is a dual specificity protein kinase which autophosphorylates on Tyr-530 and phosphorylates exogenous substrates on Ser/Thr residues.

Myelin basic protein induces cell death of mature pig oligodendrocytes in vitro and produces demyelination in vivo

2000 ◽  
Vol 283 (1) ◽  
pp. 77-80 ◽  
Author(s):  
Hans H Althaus ◽  
Sabine Klöppner ◽  
Gerlinde Rohde ◽  
Nahid Parvizi ◽  
Peter Schwartz ◽  
...  
Keyword(s):  
Cell Death ◽  
Myelin Basic Protein ◽  
Basic Protein

Myelin basic protein-reactive T cells induce conduction failure in vivo but not in vitro

Neuroreport ◽  
2003 ◽  
pp. 317-320 ◽  
Author(s):  
J??r??me Devaux ◽  
Claude Forni ◽  
Christine Beeton ◽  
Jocelyne Barbaria ◽  
Evelyne B??raud ◽  
...  
Keyword(s):  
T Cells ◽  
Myelin Basic Protein ◽  
Basic Protein ◽  
Conduction Failure
Sign in / Sign up

Export Citation Format

Share Document