| The luminal domain of TGN 38 interacts with integrin beta 1 and is involved in its trafficking . ^^^ Unexpectedly , in these cells , TGN 38 colocalizes with integrin alpha 5 beta 1 at the Golgi , the cell surface or in the footprints and an increased amount of both integrin subunits on the plasma membrane was observed . ^^^ Under physiological conditions when TGN 38 is not overexpressed , it interacts with integrin beta 1 . ^^^ This was demonstrated by reciprocal co immunoprecipitation of integrin beta 1 and TGN 38 . ^^^ Functional analysis reveals that modification of the trafficking of TGN 38 results in a parallel change in the distribution of integrin alpha 5 beta 1 , leading to the conclusion that TGN 38 is involved in the trafficking of integrin beta 1 . . ^^^ |