We have investigated the regulation of kinases and phosphatases in early gene activation in monocytes because these cells are implicated in the pathogenesis of acute inflammatory states, such as sepsis and acute lung injury. One early gene up-regulated by endotoxin is c-Jun, a member of the activating protein (AP) family. C-Jun is phosphorylated by c-Jun N-terminal kinase (JNK) and associates w...

Three-dimensional models of thrombin complexed with large fragments of the fibrinogen Aalpha and Bbeta chains are presented. The models are consistent with the results of recent mutagenesis studies of thrombin and with the information available on naturally occurring fibrinogen mutants. Thrombin recognizes fibrinogen with an extended binding surface, key elements of which are Tyr(76) in exosite...

The PR65/A subunit of protein phosphatase 2A serves as a scaffolding molecule to coordinate the assembly of the catalytic subunit and a variable regulatory B subunit, generating functionally diverse heterotrimers. Mutations of the beta isoform of PR65 are associated with lung and colon tumors. The crystal structure of the PR65/Aalpha subunit, at 2.3 A resolution, reveals the conformation of its...

PURPOSE Reversible protein phosphorylation is a fundamental regulatory mechanism in all biologic processes. Protein serine/threonine phosphatases-1 (PP-1) and 2A (PP-2A) account for 90% of serine/threonine phosphatase activity in eukaryote cells and play distinct roles in regulating multiple cellular processes and activities. Our previous studies have established the expression patterns of the ...

Alfimeprase (ALF) is a recombinant, truncated form of fibrolase, a directly fibrinolytic zinc metalloproteinase that was first isolated from the venom of the Southern copperhead snake (Agkistrodon contortrix contortrix). ALF has direct proteolytic activity against the fibrin(ogen) Aalpha chain. ALF can be covalently bound and neutralized by serum alpha2-macroglobulin, a prevalent mammalian prot...

For many years, calcineurin has been a familiar molecule as a target of the immunosuppressive agents cyclosporin A and FK-506. Calcineurin inhibition interferes with T cell signaling by preventing activation of the transcription factor NFATc. However, calcineurin is expressed in most tissues in the body, and calcineurin inhibition undoubtedly alters many other cellular processes. As a result, s...

Alfimeprase is a recombinantly produced, truncated form of fibrolase, a known directly fibrinolytic zinc metalloproteinase that was first isolated from the venom of the southern copperhead snake (Agkistrodon contortrix contortrix). Both fibrolase and alfimeprase have been shown to have direct proteolytic activity against the fibrinogen Aalpha chain. In vivo pharmacology studies have shown that ...

New findings reveal that the calcineurin-NFAT signaling pathway helps to promote osteoblast differentiation. Three recent papers reveal somewhat different mechanisms by which this could occur. In one study, transduction of calcineurin Aalpha increased expression of osteoblast differentiation markers, including Runx-2. In another study, NFATc1 cooperatively enhanced Osterix activation of the col...

The kinetics of release of fibrinopeptide A (FPA) and B (FPB) by thrombin were investigated on unfractionated fibrinogen samples as a function of CaCl(2) concentration. A 50 mM Tris, 104 mM NaCl, pH 7.4 (TBS) buffer, to which 1 mM EDTA-Na(2) (TBE) or 2.5 (TBC2.5), 14 (TBC14), and 30 mM CaCl(2) (TBC30) was alternatively added, was employed. The % FPA versus time curves were fitted with single st...