Identified proteins UniprotKB acc. entry Mascot score Th. Mw (Da) # unique peptides HLA class I histocompatibility antigen, A-3 alpha chain 1A03_HUMAN 408 40815 3 HLA class I histocompatibility antigen, B-44 alpha chain 1B44_HUMAN 188 40456 2 HLA class I histocompatibility antigen, Cw-12 alpha chain 1C12_HUMAN 428 40860 3 Apolipoprotein O APOO_HUMAN 66 22271 2 Serine-protein kinase ATM ATM_HUMAN 39 350419 2 ATP synthase subunit e, mitochondrial ATP5I_HUMAN 54 7928 3 B-cell receptor-associated protein 31 BAP31_HUMAN 82 27974 2 Apoptosis regulator Bcl-2 BCL2_HUMAN 46 26249 2 CDC42 small effector protein 2 C42S2_HUMAN 47 9217 2 Glutathione S-transferase kappa 1 GSTK1_HUMAN 89 25480 2 3-hydroxyacyl-CoA dehydrogenase type-2 HCD2_HUMAN 73 26906 2 Intercellular adhesion molecule 3 ICAM3_HUMAN 52 59503 2 Integrin alpha-L/CD11a ITAL_HUMAN 72 128688 5 Multidrug resistance protein 1 MDR1_HUMAN 136 141373 4 Microsomal glutathione S-transferase 3 MGST3_HUMAN 66 16506 2 Torsin-1A-interacting protein 1 TOIP1_HUMAN 85 66208 3

Table 1: Proteins observed to be exclusively present in DRMs of resting CD3+ T cells. The table lists all proteins solely observed in DRMs from resting human primary T cells including their UniProt Knowledgebase accession entry, total Mascot score, theoretical molecular mass (Th. Mw) and number (#) of unique peptides identified. The table represents combined data from three separate experiments and all proteins had to be identified in at least two individual experiments in order to be included.