title: Electrochemical detection of receptor-mediated endocytosis by scanning electrochemical microscopy.
abstract: We report a scanning electrochemical microscopy (SECM)-based receptor-mediated endocytosis detection method. Epidermal growth factor receptor (EGFR), which is one of the key membrane proteins associated with cancer, was used as a model for receptor-mediated endocytosis. EGFR molecules on the outer cell membrane were detected by SECM by using alkaline phosphatase (ALP) as a labeling enzyme. Since SECM detected the ALP activity on the outer membrane, the procedure helped discriminate the EGFR on the outer membrane from the intracellular EGFR involved in endocytosis. SECM showed a marked decrease in the current responses generated due to ALP activity by 93% on addition of the epidermal growth factor, indicating clearly that EGF triggered the endocytosis, which led to the withdrawal of most EGFRs from the outer membrane.
authors.affiliation: Graduate School of Environmental Studies, Tohoku University, Aramaki, Aoba, Sendai, Japan. yasufumi1981@hotmail.com
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miyamoto
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Shiku
authors.forename: Kosuke
authors.initials: K
authors.lastname: Ino
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Yasukawa
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Asano
authors.forename: Izumi
authors.initials: I
authors.lastname: Kumagai
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Matsue
mesh_terms: D000469:Alkaline Phosphatase / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D016466:CHO Cells; D002462:Cell Membrane / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D002478:Cells, Cultured; D006224:Cricetinae; D055664:Electrochemical Techniques / Q000379:methods*; D004563:Electrochemistry; D004705:Endocytosis; D066246:ErbB Receptors / Q000737:chemistry / Q000378:metabolism*; D006801:Humans
chemical_list: D066246:ErbB Receptors; D000469:Alkaline Phosphatase