Skip to main page content
U.S. flag

An official website of the United States government

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1982 Dec 1;156(6):1622-34.
doi: 10.1084/jem.156.6.1622.

Differential regulation of membrane and secretory mu chain synthesis in human beta cell lines. Regulation of membrane mu or secreted mu

L Hendershot, D Levitt

Differential regulation of membrane and secretory mu chain synthesis in human beta cell lines. Regulation of membrane mu or secreted mu

L Hendershot et al. J Exp Med. .

Abstract

Regulation of membrane and secretory mu synthesis was examined in human lymphoblastoid cell lines representing various stages of differentiation. Immunoglobulin phenotype was determined by surface and cytoplasmic staining with fluorochrome-conjugated antibodies and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of anti-mu precipitable cellular products. The thymidine analogue, 5-bromo-2'-deoxyuridine (BUdR), which inhibits differentiation-specific proteins in a variety of systems, was used to examine regulation of immunoglobulin synthesis. We found that BUdR had a differential effect on membrane (mum) and secretory (mus) type mu heavy chains. Ig production in pre-B and plasma cell-like lines, which make mus, was unaffected by BUdR. However, surface expression of IgM (mum) in B cell lines was drastically inhibited at similar doses of BUdR without diminishing total Ig or protein synthesis. Examination of labeled mu chains from control and BUdR-treated B cell lines by SDS-PAGE revealed the production of two sizes of mu (mum and mus) in control cells and only the smaller size (mus) in BUdR-treated cells. This size difference could not be attributed to alterations in glycosylation of the molecules. These data show that BUdR inhibits the production of membrane mu chains without diminishing secretory mu chain synthesis in the same cell. Our findings suggest that thymidine-rich regions of the genome are involved in the regulation of mum vs. mus during B cell differentiation.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Science. 1967 Sep 1;157(3792):1064-5 - PubMed
    1. Biochem J. 1969 Jun;113(2):299-305 - PubMed
    1. Nature. 1970 Aug 15;227(5259):680-5 - PubMed
    1. Biochem Biophys Res Commun. 1970 Jul 27;40(2):284-9 - PubMed
    1. J Exp Med. 1973 Sep 1;138(3):557-73 - PubMed

Publication types