| First Author | Matsuuchi L | Year | 1992 |
| Journal | Proc Natl Acad Sci U S A | Volume | 89 |
| Issue | 8 | Pages | 3404-8 |
| PubMed ID | 1373499 | Mgi Jnum | J:94881 |
| Mgi Id | MGI:3521842 | Doi | 10.1073/pnas.89.8.3404 |
| Citation | Matsuuchi L, et al. (1992) The membrane IgM-associated proteins MB-1 and Ig-beta are sufficient to promote surface expression of a partially functional B-cell antigen receptor in a nonlymphoid cell line. Proc Natl Acad Sci U S A 89(8):3404-8 |
| abstractText | The B-cell antigen receptors consist of membrane immunoglobulins (mIgs) noncovalently associated with two accessory proteins, MB-1 and Ig-beta. We used transfection into a nonlymphoid cell line to test whether MB-1 and Ig-beta were sufficient to promote cell surface expression of mIgM capable of signal transduction. Expression of MB-1 and Ig-beta, but not MB-1 alone, allowed high-level surface expression of mIgM in the AtT20 endocrine cell line, which presumably lacks other B-cell-specific components. The reconstituted antigen receptor was capable of mediating some of the signaling reactions characteristic of mIgM in B lymphocytes. Crosslinking mIgM on transfected AtT20 cells stimulated tyrosine phosphorylation of MB-1 and Ig-beta and also increased the amount of phosphatidylinositol 3-kinase activity that could be precipitated with anti-phosphotyrosine antibodies. When total cell lysates were analyzed by anti-phosphotyrosine immunoblotting, however, no induced phosphorylation of more abundant proteins was detected. Moreover, crosslinking of the receptor in AtT20 cells did not stimulate inositol phospholipid breakdown. Thus, the transfected B-cell antigen receptor could initiate some signal transduction events but AtT20 cells may lack components required for other signaling events associated with mIgM. |
