Epithin/PRSS14 proteolytically regulates angiopoietin receptor Tie2 during transendothelial migration

Abstract

Epithin/PRSS14, a type II transmembrane serine protease, is involved in normal epithelial development and tumor progression. Here we report, as an interacting substrate of epithin, a receptor tyrosine kinase Tie2 that is well known for important roles in the vessel stability.

Filamin A Is Required in Injured Axons for HDAC5 Activity and Axon Regeneration

“…Proteins were separated by SDS-PAGE and detected by silver staining (Life Technologies). Proteins were identified as described previously (27). Briefly, protein bands were excised, destained, and trypsinized.…”

Shedding of epithin/PRSS14 is induced by TGF-β and mediated by tumor necrosis factor-α converting enzyme

“…When the gene is expressed in the skin by keratin 5 promoter, skin tumors appear spontaneously and tumorigenesis can be facilitated by chemical carcinogens or tumor promoters [9]. Earlier, we reported the critical roles of epithin/PRSS14 in angiogenesis [10], epithelial-mesenchymal transition (EMT) [11], and transendothelial migration in vitro and tumor metastasis of 4T1 breast cancer cells in vivo [7,12]. Soluble epithin/PRSS14 protein shed from the cancer cells shows the angiogenic activities [10].…”

Calmodulin Mediates Ca 2+ -Dependent Inhibition of Tie2 Signaling and Acts as a Developmental Brake During Embryonic Angiogenesis

“…Next, to investigate the molecular mechanism underlying the calcium-induced Tie2 dephosphorylation, we used a constitutively active form of Tie2, Tie2ΔECD, 22 expressed in human embryonic kidney 293T cells (HEK293T). The Tie2 mutant lacking the extracellular domain (ECD) was properly targeted to the cell surface ( Figure IIA in the online-only Data Supplement) and exhibited a high level of ligand-independent phosphorylation ( Figure 1C, lane 2) as previously reported.…”

“…The Tie2 mutant lacking the extracellular domain (ECD) was properly targeted to the cell surface ( Figure IIA in the online-only Data Supplement) and exhibited a high level of ligand-independent phosphorylation ( Figure 1C, lane 2) as previously reported. 22 This might be attributed to its propensity to dimerize, even in the absence of a ligand, through its coiled-coil domain in the membrane proximal region of the Tie2 cytoplasmic tail. 22 Unlike the endogenous Tie2 protein expressed in HUVECs, however, calcium ionophore treatment did not reduce the phosphorylation of Tie2ΔECD, ectopically expressed in HEK293T cells ( Figure 1C, lane 3).…”

“…22 This might be attributed to its propensity to dimerize, even in the absence of a ligand, through its coiled-coil domain in the membrane proximal region of the Tie2 cytoplasmic tail. 22 Unlike the endogenous Tie2 protein expressed in HUVECs, however, calcium ionophore treatment did not reduce the phosphorylation of Tie2ΔECD, ectopically expressed in HEK293T cells ( Figure 1C, lane 3). We reasoned that this might result from the amount of ectopically expressed Tie2 molecules, which exceeds the relatively lower amount of, if any, an endogenously expressed calcium effector molecule.…”