title: Identification of TrkA on living PC12 cells by atomic force microscopy.
abstract: In neural cells, nerve growth factor (NGF) initiates its survival signal through the binding to its cell surface receptor tyrosine kinase A (TrkA). Understanding the pattern of TrkA distribution and association in living cells can provide a fingerprint for the diagnostic comparison with alterations underlying ligand-receptor dysfunction seen in various neurological diseases. In this study, we use the NGF-TrkA-specific interaction as a probe to identify TrkA on living PC12 cell by atomic force microscopy (AFM). An NGF-modified AFM tip was used to perform force volume (FV) imaging, generating a 2D force map to illustrate the distribution and association of TrkA on PC12 cell membrane. It is found that TrkA is highly aggregated at local regions of the cell. This unique protein association may be required to promote its function as a receptor of NGF. The methodology that we developed in this study can be adapted by other systems, thus providing a general tool for investigating protein association in its natural environment.
authors.affiliation: Department of Biological, Chemical and Physical Sciences, Illinois Institute of Technology, Chicago, IL 60616, USA.
authors.forename: C V Gopal
authors.initials: CV
authors.lastname: Reddy
authors.forename: Krystyna
authors.initials: K
authors.lastname: Malinowska
authors.forename: Nick
authors.initials: N
authors.lastname: Menhart
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
mesh_terms: D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism / Q000502:physiology; D007091:Image Processing, Computer-Assisted; D018625:Microscopy, Atomic Force; D020932:Nerve Growth Factor / Q000378:metabolism; D009474:Neurons / Q000737:chemistry* / Q000166:cytology; D016716:PC12 Cells; D011485:Protein Binding; D051381:Rats; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism; D020917:Receptor, trkA / Q000032:analysis* / Q000378:metabolism / Q000502:physiology
chemical_list: D020800:Receptor, Nerve Growth Factor; D020932:Nerve Growth Factor; D020917:Receptor, trkA