Identified proteins UniprotKB acc. entry Mascot score Th. Mw (Da) # unique peptides AFG3-like protein 2 AFG32_HUMAN 104 88528 2 Acylglycerol kinase, mitochondrial AGK_HUMAN 71 47107 2 Annexin A5 ANXA5_HUMAN 67 35914 2 Cell division control protein 42 CDC42_HUMAN 83 21297 2 Cytosolic non-specific dipeptidase CNDP2_HUMAN 36 52845 2 Cullin-3 CUL3_HUMAN 67 88873 2 Drebrin-like protein DBNL_HUMAN 61 48178 2 Drebrin DREB_HUMAN 76 71385 2 Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit γ-7 GBG7_HUMAN 53 7517 2 Granzyme M GRAM_HUMAN 54 27428 2 Interleukin enhancer-binding factor 3 ILF3_HUMAN 163 95279 4 cAMP-dependent protein kinase type II-alpha regulatory subunit KAP2_HUMAN 53 45490 3 Glycogen phosphorylase, brain form PYGB_HUMAN 48 96635 2 SH3 domain-containing kinase-binding protein 1/CIN85 SH3K1_HUMAN 140 73082 4 Antigen peptide transporter 2 TAP2_HUMAN 39 75616 2 Tricarboxylate transport protein, mitochondrial TXTP_HUMAN 99 33991 3 General vesicular transport factor p115 USO1_HUMAN 46 107828 2 Vinculin VINC_HUMAN 96 123722 2 Tyrosine-protein kinase ZAP-70 ZAP70_HUMAN 55 69827 3

Table 2: Proteins observed to be exclusively present in DRMs of stimulated CD3+ T cells. The table lists all proteins solely observed in DRMs from human primary T cells upon CD3/CD28 co-stimulation 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.