Endoprotease activities other than furin and PACE4 with a role in processing of HIV-I gp160 glycoproteins in CHO-K1 cells.
We addressed the question of whether furin is the endoprotease primarily responsible for processing the human immunodeficiency virus type I (HIV-I) envelope protein gp160 in mammalian cells. The furin-deficient Chinese hamster ovary (CHO)-K1 strain RPE.40 processed gp160 as efficiently as wild-type CHO-K1 cells in vivo. Although furin can process gp160 in vitro, this processing is probably not physiologically relevent, because it occurs with very low efficiency. PACE4, a furin homologue, allowed processing of gp160 when both were expressed in RPE.40 cells. Further, PACE4 participated in the activation of a calcium-independent protease activity in RPE.40 cells, which efficiently processed the gp160 precursor in vitro. This calcium-independent protease activity was not found in another furin-deficient cell strain, 7.P15, selected from the monkey kidney cell line COS-7.
Inocencio
N M
NM
Department of Microbiology and Molecular Genetics, Markey Center for Molecular Genetics, University of Vermont, Burlington 05405, USA.
Sucic
J F
JF
Moehring
J M
JM
Spence
M J
MJ
Moehring
T J
TJ
D017500:Adenovirus E1A Proteins / Q000378:metabolism; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D004492:Edetic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D045683:Furin; D019302:HIV Envelope Protein gp160 / Q000378:metabolism*; D006801:Humans; D043484:Proprotein Convertases; D011480:Protease Inhibitors / Q000494:pharmacology; D012697:Serine Endopeptidases / Q000378:metabolism*; D013381:Subtilisins / Q000378:metabolism*
D017500:Adenovirus E1A Proteins; C084301:E1A protein 243R, Human adenovirus type 5; D019302:HIV Envelope Protein gp160; D011480:Protease Inhibitors; D004533:Egtazic Acid; D004492:Edetic Acid; C080654:PCSK6 protein, human; D043484:Proprotein Convertases; D012697:Serine Endopeptidases; D013381:Subtilisins; D045683:Furin