| These findings reveal that LRP1B is a novel binding partner of APP that functions to decrease APP processing to Abeta . ^^^ Since LRP1B has overlapping ligand binding properties with LRP , we investigated whether LRP1B , like LRP , could interact with the beta amyloid precursor protein ( APP ) and modulate its processing to amyloid beta peptides ( Abetas ) . ^^^ Using an LRP1B minireceptor ( mLRP1B4 ) generated to study the trafficking of LRP1B , we found that mLRP1B4 and APP form an immunoprecipitable complex . ^^^ A functional consequence of mLRP1B4 expression was a significant accumulation of APP at the cell surface , which is likely related to the slow endocytosis rate of LRP1B . ^^^ |