Table 2. Y2H assays for interactions between the enamel matrix proteins and membrane-bound proteins.
The DNA inserts in the pGBKT7 and pGADT7 vectors encode the corresponding protein fragments. In the β-galactosidase activity assay, a positive reaction evident after 6 h is recorded as ++, and a positive reaction evident only after 20 h is recorded as +.
| Row | Insert of pGBKT7 vector | Insert of pGADT7 vector | β-Galactosidase activity |
|---|---|---|---|
| a | No insert | No insert | − |
| b | Amelogenin-(1–180) | CD63-(1–238) | ++ |
| c | Ameloblastin-(1–396) | CD63-(1–238) | ++ |
| d | Enamelin-(1–1236) | CD63-(1–238) | ++ |
| e | Amelogenin-(1–180) | LAMP1-(1–386) | ++ |
| f | Amelogenin-(1–180) | CD63-(103–205) | ++ |
| g | Ameloblastin-(1–396) | CD63-(103–205) | ++ |
| h | Enamelin-(1–1236) | CD63-(103–205) | ++ |
| i | Amelogenin-(1–180) | CD63-(165–205) | ++ |
| j | Amelogenin-(3–33) | LAMP1-(1–121) | − |
| k | Amelogenin-(3–33) | LAMP1-(95–251) | − |
| l | Amelogenin-(3–33) | LAMP1-(226–361) | − |
| m | Amelogenin-(3–33) | LAMP1-(342–386) | − |
| n | Amelogenin-(3–33) | LAMP1-(1–386) | − |
| o | Amelogenin-(155–179) | LAMP1-(1–121) | (+)* |
| p | Amelogenin-(155–179) | LAMP1-(95–251) | ++† |
| q | Amelogenin-(155–179) | LAMP1-(226–361) | +† |
| r | Amelogenin-(155–179) | LAMP1-(342–386) | − |
| s | Amelogenin-(155–179) | LAMP1-(1–386) | ++ |
| t | Amelogenin-(155–168) | LAMP1-(226–251) | ++ |
| u | Amelogenin-(155–168) | LAMP2-(227–259) | ++ |
| v | Amelogenin-(155–168) | CD63-(165–205) | ++ |
| w | Amelogenin-(169–179) | LAMP1-(226–251) | − |
| x | Amelogenin-(169–179) | LAMP2-(227–259) | − |
| y | Amelogenin-(169–179) | CD63-(165–205) | − |
| z | p53 | SV40 large T-antigen | + |
* The reaction is noticeably weaker than the reaction at the row q.
† The LAMP1–amelogenin-interacting region was concluded to be the overlapping region of LAMP1 identified from the reactions seen in rows p and q.