| Identification of snapin and three novel proteins ( BLOS 1 , BLOS 2 , and BLOS3 / reduced pigmentation ) as subunits of biogenesis of lysosome related organelles complex 1 ( BLOC 1 ) . ^^^ Using specific antibodies to detect endogenous proteins from human and mouse cells , we found that Snapin , BLOS 1 , BLOS 2 , and BLOS 3 co immunoprecipitate , and co fractionate upon size exclusion chromatography , with previously known BLOC 1 subunits . ^^^ |