fˌɑːsfoːɹɪlˈeɪʃən ʌv sˈɛɹiːn ænd θɹɪˈɑːnaɪn ɹˈɛsɪdˌuːz ɪz kənsˈɜːvd dˈʊɹɹɪŋ ˌɛmˌeɪtʃsˈiː klˈæs aɪ ænd ˌɛmˌeɪtʃsˈiː klˈæs ɹˌoʊmən tˈuː ˈæntɪdʒˌɛn pɹˈɑːsɛsɪŋ.
Phosphorylation of serine and threonine residues is conserved during MHC class I and MHC class II antigen processing.