Table 2. Frequency of putative hydrophobic and aromatic ER export motifs in the cytoplasmic tails of type I transmembrane proteins.
| Motif | Proteins |
Human
|
Mouse
|
Citations | ||||
|---|---|---|---|---|---|---|---|---|
| Expected occurrences | Actual occurrences | % difference | Expected occurrences | Actual occurrences | % difference | |||
| RL | GABA transporter 1 | 800 | 763 | -4.6 | 663 | 657 | -0.9 | [27] |
| Terminal LL | ERGIC-53 | 6.8 | 10 | 47 | 5.9 | 8 | 36 | [31] |
| Terminal II | ERGIC-53 | 1.3 | 2 | 54 | 1.1 | 3 | 173 | [31] |
| Terminal V | Stem cell factor, ERGIC-53, CD8α, Frizzled4, FXYD7, HLA-F | 53 | 145 | 174 | 43 | 114 | 165 | [31,33,87,88,104] |
| Terminal I | 36 | 64 | 78 | 29 | 66 | 128 | [31] | |
| Terminal A | 65 | 105 | 62 | 50 | 86 | 72 | ||
| Terminal L | 82 | 102 | 24.4 | 68 | 76 | 11.8 | ||
| F at -2 | ERGIC-53 | 28 | 30 | 7.1 | 23 | 26 | 13 | [31] |
| Y at -2 | ERGIC-53 | 31 | 40 | 29 | 25 | 28 | 12 | [31] |
| FF | ERGIC-53, p24 | 119 | 101 | -15 | 98 | 85 | -13 | [28,105-107] |
| YY | ERGIC-53 | 146 | 130 | -11 | 124 | 107 | -14 | [31] |
| FY | Erv46p | 132 | 104 | -21 | 110 | 80 | -27 | [107] |
| YF | 132 | 123 | -7 | 110 | 101 | -8 | ||
The expected random number of occurrences of each motif in the cytoplasmic tails of 984 human or 782 mouse non-redundant type I transmembrane proteins is compared with the actual number of occurrences of the motif. The % difference was calculated as % 100 * (actual occurrences – expected occurrences / expected occurrences).