Proteins possess distinct intracellular roles allowing them to have vast therapeutic applications. However, due to poor cellular permeability and fragility of most proteins, intracellular delivery of native, active proteins is challenging. We describe a biomimetic protein delivery vehicle which is degradable upon the digestion by furin, a ubiquitous intracellular protease, to release encapsulat...

Brain-derived neurotrophic factor (BDNF) is secreted as either a mature furin-processed form or an unprocessed pro-form. Here, we characterise the extracellular processing of pro-BDNF by the serine protease plasmin. Using recombinant BDNF, maintained in the pro-form by site-directed mutagenesis or inhibition of furin, we demonstrate that plasmin (but not related proteases) is a specific and eff...

Proteolytic maturation of various precursor proteins by the proprotein convertase Furin is now considered as a crucial step in tumor progression and metastasis. Here, we report the repression of the malignant and metastatic potential of carcinoma cells by the prodomain region of Furin (ppFurin), a naturally occurring inhibitor of this convertase. Overexpression of ppFurin in carcinoma cells in ...

PC2 and furin are two recently identified members of a class of mammalian proteins homologous to the yeast precursor processing protease kex2 and the bacterial subtillisins. We have used the polymerase chain reaction to identify and clone a cDNA (PC3) from the mouse AtT20 anterior pituitary cell line that represents an additional member of this growing family of mammalian proteases. PC3 encodes...

Limited proteolysis, accomplished by endopeptidases, is a ubiquitous phenomenon underlying the regulation and activation of many enzymes, receptors, and other proteins synthesized as inactive precursors. Serine proteases make up one of the largest and most conserved families of endopeptidases involved in diverse cellular activities, including wound healing, blood coagulation, and immune respons...

Glycoprotein B (gB) of bovine herpesvirus 1 (BHV-1) is essential for BHV-1 replication and is required for membrane fusion processes leading to virus penetration into the target cell and direct spreading of BHV-1 from infected to adjacent noninfected cells. Like many of the herpesvirus gB homologs, BHV-1 gB is proteolytically processed by furin, an endoproteinase localized in the trans-Golgi ne...

In neuroendocrine cells sorting of proteins from immature secretory granules (ISGs) occurs during maturation and is achieved by clathrin-coated vesicles containing the adaptor protein (AP)-1. We have investigated the role of the mannose-6-phosphate receptors (M6PRs) in the recruitment of AP-1 to ISGs. M6PRs were detected in ISGs isolated from PC12 cells by subcellular fractionation, and by immu...

BACKGROUND In zebrafish, vascular endothelial growth factor-C precursor (proVEGF-C) processing occurs within the dibasic motif HSIIRR(214) suggesting the involvement of one or more basic amino acid-specific proprotein convertases (PCs) in this process. In the present study, we examined zebrafish proVEGF-C expression and processing and the effect of unprocessed proVEGF-C on caudal fin regenerati...

Papillomaviruses (PV) comprise a large family of nonenveloped DNA viruses that include the oncogenic PV types that are the causative agents of human cervical cancer. As is true of many animal DNA viruses, PV are taken into the cell by endocytosis and must escape from the endosomal compartment to the cytoplasm to initiate infection. Here we show that this step depends on the site-specific enzyma...

Feline coronaviruses (FCoV) exist as 2 biotypes: feline enteric coronavirus (FECV) and feline infectious peritonitis virus (FIPV). FECV causes subclinical infections; FIPV causes feline infectious peritonitis (FIP), a systemic and fatal disease. It is thought that mutations in FECV enable infection of macrophages, causing FIP. However, the molecular basis for this biotype switch is unknown. We ...