The reduced folate carrier in L1210 murine leukemia cells is a 58-kDa protein

• Published in: Biochimica et biophysica acta Vol. 1466; no. 1; pp. 7 - 10
• Main Authors: Zhao, Rongbao, Gao, Feng, Liu, Laibin, Goldman, I.David
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.06.2000
• Subjects: Animals; Carrier Proteins - chemistry; Carrier Proteins - immunology; Carrier Proteins - isolation & purification; Carrier Proteins - metabolism; Carrier proteolysis; Cell Membrane - metabolism; Dithiothreitol; Electrophoresis, Polyacrylamide Gel - methods; Folate transport; Heating; Indicators and Reagents; Intestines - chemistry; Membrane Proteins - chemistry; Membrane Proteins - immunology; Membrane Proteins - isolation & purification; Membrane Proteins - metabolism; Membrane proteolysis; Membrane Transport Proteins; Mice; Rabbits; Reduced folate carrier; Transport; Tumor Cells, Cultured; Reduced folate carrier; Carrier proteolysis; Membrane proteolysis; Transport; Folate transport
• ISSN: 0005-2736; 0006-3002; 1879-2642
• DOI: 10.1016/S0005-2736(00)00190-5

The reduced folate carrier (RFC1) is a major transporter for both natural reduced folates and antifolate chemotherapeutics. Using polyclonal antibodies targeted to epitopes at the loop between the sixth and seventh predicted transmembrane domains or the distal C-terminus, we were able to demonstrate by Western blot analysis that the molecular size of RFC1 expressed in murine leukemia L1210 cells is 58 kDa as predicted by the open reading frame of its cDNA. 46- and 38-kDa proteins detected only in plasma membrane preparations were proteolytic degradation products that appeared during membrane preparation or treatment with the conventional SDS–PAGE loading buffer. These data resolve discrepancies reported previously for the molecular size of RFC1.