Synthesis of plasminogen activator inhibitor 1 by bovine mammary epithelial and myoepithelial cell lines.
Conversion of plasminogen to plasmin provides an important source of proteolytic activity in the bovine mammary gland. Plasminogen activator inhibitor 1 (PAI-1) plays a key role in limiting plasminogen activation. The PAI-1 biosynthetic capabilities of various bovine mammary cells were determined. The immortalized epithelial cell lines MAC-T and BME-UV and the myoepithelial cell line BMM-UV were used as model systems. Northern blot analysis indicated that both epithelial and myoepithelial cells contained PAI-1 mRNA. Bovine PAI-1 was encoded by a single mRNA species approximately 3.0 kb long. BME-UV cells contained 2.0-fold (P < 0.01) the PAI-1 mRNA of MAC-T or BMM-UV cells. Reverse zymography indicated that both epithelial and myoepithelial cells synthesized PAI-1 protein with a molecular mass of approximately 50 kDa.
Zavizion
B
B
Department of Animal and Food Sciences, University of Vermont, Burlington 05404, USA.
Heegard
C W
CW
White
J
J
Cheli
F
F
Politis
I
I
D000818:Animals; D015152:Blotting, Northern; D002417:Cattle; D002460:Cell Line; D003470:Culture Media; D004848:Epithelium / Q000378:metabolism; D005260:Female; D006801:Humans; D007163:Immunosorbent Techniques; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008970:Molecular Weight; D017395:Plasminogen Activator Inhibitor 1 / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis
D003470:Culture Media; D017395:Plasminogen Activator Inhibitor 1; D012333:RNA, Messenger