Shown here in green a portion of the invariant chain binds to the peptide. Binding groove at the MHC-class 2 molecule and prevents peptides are unfolded proteins present in the ER from binding the invariant chain also guides the chains for the past molecule out at the ER and through the Golgi apparatus into a vesicle eventually become part at the end acidic pathway by which pathogens and foreign protein are taken into the cell aggressive acidification and this and acidic classical have to teach pretty a SES the cleve in invariant chain into places leaving small peptide the class to associate invariant chain peptide or clip down to the class 2 molecule engulfed pathogens where their protein are also degraded by ass inactivated pretty aces into peptide these cannot immediately buy into the class 2 molecule because the clip peptide still occupies the peptide binding grew the removal and the clip peptide is the function at the specialized MHC class to like molecule Hl a DM which is also present in these vesicles it function as a catalyst coordinating both the release obliquely peptide from Class two molecule and the binding a pathogen derived peptide the MHC class to peptide complex is then transported to the cell surface where it can be recognized by the antigen receptor CD4+ T cell