Receptor Degradation Assay.pdf

Cells were incubated at 25°C for 1 hour and receptor number was determined after 24 hours of isoproterenol treatment. MG132 or lactacystin was added to cells 1 hour before stimulation. Flag epitope–tagged WT-b2AR and b2AR22 were transiently transfected in COS-7 cells and immunoprecipitated with Flag affinity beads. Ubiquitinated species were detected with antibody Ub P4D1. Coimmunoprecipitation of endogenous proteins from whole-brain extract was analyzed by SDS-PAGE and detected by immunoblot analysis. Recombinant b2AR reconstituted in vesicles was used as the substrate in a ubiquitination reaction. Mdm2 truncation mutants were prepared by standard polymerase chain reaction protocols. Flag epitope–tagged b2ARs expressed in HEK293 cells were treated with or without isoproterenol and receptor internalization was quantified by flow cytometry.

A "bottom-up" approach was used to assemble functional device elements and element arrays from solution using electronically well-defined semiconductor nanowire building blocks. Crossed nanowire p-n junctions and junction arrays were assembled with controllable electrical characteristics. These junctions were used to create integrated nanoscale field-effect transistor arrays with nanowires as both the conducting channel and gate electrode. Nanowire junction arrays were configured as key OR, AND, and NOR logic-gate structures with substantial gain and used to implement basic computation.