Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.6 (thromboplastin)
 13,278 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Osteoprotegerin ligand (OPGL) is a key regulator of formation and activation of osteoclasts. In the present study, the cDNA encoding the extracellular domain of murine OPGL (sOPGL) was synthesized by RT-PCR and cloned into fusion expression vector pET-42a(+) in a certain strategy on purpose that the fusion tag could be completely removed by factor Xa from the expressed fusion protein without any vector-encoded sequence left. Induced with IPTG, the recombinant E. Coli cells produced a 47 kD protein in high level that could be recognized, through Western blotting analysis, by the antibody against OPGL. The expressed products were purified through Glutathione-sepharose 4B affinity chromatography. Along with the fusion molecule, a protein about 30 kD was also specifically bound to the resin. The 30 kD molecule could be recognized by polyclonal antibody against GST-IGF-1, but not by antibody against OPGL. It suggested that the 30 kD molecule was derived from the degradation of the fusion protein. After the cleavage with factor Xa and further purification, the fusion tag was removed and the recombinant sOPGL was obtained. Finally, we confirmed that the recombinant sOPGL could promote osteoclast formation from mouse bone marrow cells in a dose dependent manner.
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PMID:Expression, purification and bioactivity characterization of extracellular domain of murine osteoprotegerin ligand. 1547 18

Prothrombin is converted to thrombin by factor Xa in the cell-associated prothrombinase complex. Prothrombin is present in calcified bone matrix and thrombin exerts effects on osteoblasts as well as on bone resorption by osteoclasts. We investigated whether (1) osteoclasts display factor Xa-dependent prothrombinase activity and (2) osteoclasts express critical regulatory components upstream of the prothrombinase complex. The osteoclast differentiation factor RANKL induced formation of multinucleated TRAP positive cells concomitant with induction of prothrombinase activity in cultures of RAW 264.7 cells and bone marrow osteoclast progenitors. Expression analysis of extrinsic coagulation factors revealed that RANKL enhanced protein levels of factor Xa as well as of coagulation factor III (tissue factor). Inhibition assays indicated that factor Xa and tissue factor were involved in the control of prothrombinase activity in RANKL-differentiated osteoclasts, presumably at two stages (1) conversion of prothrombin to thrombin and (2) conversion of factor X to factor Xa, respectively. Activation of the extrinsic coagulation pathway during osteoclast differentiation through induction of tissue factor and factor Xa by a RANKL-dependent pathway indicates a novel role for osteoclasts in converting prothrombin to thrombin.
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PMID:RANKL induces components of the extrinsic coagulation pathway in osteoclasts. 2021 89