TY - JOUR
T1 - Developmental regulation of IgM secretion
T2 - The role of the carboxy-terminal cysteine
AU - Sitia, Roberto
AU - Neuberger, Michael
AU - Alberini, Cristina
AU - Bet, Paola
AU - Fra, Anna
AU - Valetti, Caterina
AU - Williams, Gareth
AU - Milstein, Cesar
N1 - Funding Information:
‘We thank L. Hendershot and J. F. Kearney for anti-BiP antibodies, F. ICalabi. R. Cancedda, A. Cattaneo, and M. Rocco for helpful discussions, and G. B. Ferrara and A. Albertini for continuous support and encouragement. Part of this work was performed when R. S. was recipient of a fellowship from European Molecular Biology Organization. This work was supported in part through grants from the Consiglio Nazionale Ricerche (CNR) and the Associazione ltatiana Ricerca sul Cancro (AIRC) to R. S.
PY - 1990/3/9
Y1 - 1990/3/9
N2 - B lymphocytes do not secrete IgM, and plasma cells only secrete IgM polymers. Here we show that both events are attributable to the tailpiece found at the carboxyl terminus of μs chains, and we specifically implicate Cys-575. Thus, if Cys-575 was mutated, IgM was secreted by B cells. Similarly, a mutant IgG containing a μs tailpiece became largely retained within the cell; secretion was restored upon mutation of the tailpiece cysteine. Removal of Cys-575 also allowed hypersecretion of monomeric IgM by plasmacytoma cells. Following further removal of Cμ1, heavy chains were secreted in the absence of light chains. Thus, in B and plasma cells, Cys-575 is involved both in the polymerization of IgM and in intracellular retention of unpolymerized intermediates.
AB - B lymphocytes do not secrete IgM, and plasma cells only secrete IgM polymers. Here we show that both events are attributable to the tailpiece found at the carboxyl terminus of μs chains, and we specifically implicate Cys-575. Thus, if Cys-575 was mutated, IgM was secreted by B cells. Similarly, a mutant IgG containing a μs tailpiece became largely retained within the cell; secretion was restored upon mutation of the tailpiece cysteine. Removal of Cys-575 also allowed hypersecretion of monomeric IgM by plasmacytoma cells. Following further removal of Cμ1, heavy chains were secreted in the absence of light chains. Thus, in B and plasma cells, Cys-575 is involved both in the polymerization of IgM and in intracellular retention of unpolymerized intermediates.
UR - http://www.scopus.com/inward/record.url?scp=0025230696&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025230696&partnerID=8YFLogxK
U2 - 10.1016/0092-8674(90)90092-S
DO - 10.1016/0092-8674(90)90092-S
M3 - Article
C2 - 2107027
AN - SCOPUS:0025230696
SN - 0092-8674
VL - 60
SP - 781
EP - 790
JO - Cell
JF - Cell
IS - 5
ER -