PMID- 8034695
OWN - NLM
STAT- MEDLINE
DCOM- 19940818
LR  - 20211203
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 269
IP  - 30
DP  - 1994 Jul 29
TI  - Chemotactic peptides induce phosphorylation and activation of MEK-1 in human 
      neutrophils.
PG  - 19313-20
AB  - Extracellular signal-regulated kinase (Erk) (mitogen-activated protein (MAP) 
      kinase) is rapidly activated when neutrophils are stimulated. Several isoforms of 
      MAP/Erk kinase (MEK), a kinase capable of phosphorylating and activating Erk, 
      have been identified, but their distribution and differential roles in leukocytes 
      are unknown. We studied the effect of chemotactic stimulation on MEK-1, using 
      isoform-specific antibodies. MEK-1 was found to be phosphorylated on serine and 
      threonine residues in unstimulated human neutrophils. Stimulation by the 
      chemotactic peptide formyl-methionyl-leucyl-phenylalanine (fMLP) enhanced 
      serine/threonine phosphorylation of MEK-1, while reducing its electrophoretic 
      mobility. MEK-1 activity, measured as autophosphorylation or as phosphorylation 
      of a glutathione S-transferase-Erk fusion protein, was undetectable in 
      unstimulated cells but became evident after treatment with chemoattractant. 
      Phosphorylation and activation of MEK-1 were rapid and transient, peaking after 
      1-2 min and returning to base line by 10 min. Experiments using 
      electropermeabilized cells indicated that elevation of cytosolic Ca2+ is not 
      required for activation of MEK-1 by fMLP. Moreover, MEK-1 was not stimulated by 
      either platelet-activating factor or thapsigargin, which increase Ca2+ to levels 
      comparable with those attained in chemoattractant-activated cells. In contrast, 
      activation of MEK-1 was induced by phorbol esters, and the stimulatory effect of 
      fMLP was blocked by an antagonist of protein kinase C. Stimulation of MEK-1 was 
      also blocked by concentrations of erbstatin that prevent the fMLP-induced 
      accumulation of tyrosine-phosphorylated proteins. The data suggest that MEK-1 is 
      largely responsible for the activation of Erk in chemoattractant-stimulated 
      neutrophils and that protein kinase C and/or tyrosine kinases mediate this 
      effect, whereas elevated cytosolic Ca2+ is not essential.
FAU - Grinstein, S
AU  - Grinstein S
AD  - Division of Cell Biology, Hospital for Sick Children, Toronto, Canada.
FAU - Butler, J R
AU  - Butler JR
FAU - Furuya, W
AU  - Furuya W
FAU - L'Allemain, G
AU  - L'Allemain G
FAU - Downey, G P
AU  - Downey GP
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Isoenzymes)
RN  - 0 (Recombinant Proteins)
RN  - 0 (Terpenes)
RN  - 526U7A2651 (Egtazic Acid)
RN  - 59880-97-6 (N-Formylmethionine Leucyl-Phenylalanine)
RN  - 67526-95-8 (Thapsigargin)
RN  - EC 2.5.1.18 (Glutathione Transferase)
RN  - EC 2.7.10.1 (Protein-Tyrosine Kinases)
RN  - EC 2.7.11.1 (Protein Serine-Threonine Kinases)
RN  - EC 2.7.11.13 (Protein Kinase C)
RN  - EC 2.7.12.2 (MAP Kinase Kinase 1)
RN  - EC 2.7.12.2 (MAP2K1 protein, human)
RN  - EC 2.7.12.2 (Mitogen-Activated Protein Kinase Kinases)
RN  - EC 7.2.2.10 (Calcium-Transporting ATPases)
RN  - K22DDW77C0 (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Amino Acid Sequence
MH  - Calcium/metabolism
MH  - Calcium-Transporting ATPases/antagonists & inhibitors
MH  - Egtazic Acid/analogs & derivatives/pharmacology
MH  - Enzyme Activation
MH  - Glutathione Transferase/genetics/metabolism
MH  - Humans
MH  - Isoenzymes/immunology/*metabolism
MH  - MAP Kinase Kinase 1
MH  - *Mitogen-Activated Protein Kinase Kinases
MH  - Molecular Sequence Data
MH  - N-Formylmethionine Leucyl-Phenylalanine/*pharmacology
MH  - Neutrophils/drug effects/*physiology
MH  - Phosphorylation
MH  - Protein Kinase C/metabolism
MH  - Protein Serine-Threonine Kinases/immunology/*metabolism
MH  - Protein-Tyrosine Kinases/immunology/*metabolism
MH  - Recombinant Proteins/metabolism
MH  - Terpenes/pharmacology
MH  - Thapsigargin
EDAT- 1994/07/29 00:00
MHDA- 1994/07/29 00:01
CRDT- 1994/07/29 00:00
PHST- 1994/07/29 00:00 [pubmed]
PHST- 1994/07/29 00:01 [medline]
PHST- 1994/07/29 00:00 [entrez]
AID - S0021-9258(17)32169-5 [pii]
PST - ppublish
SO  - J Biol Chem. 1994 Jul 29;269(30):19313-20.