UMMS Affiliation

Department of Molecular Genetics and Microbiology

Publication Date


Document Type



Animals; B-Lymphocytes; Cell Line; Hybridomas; Immunoglobulin A; Immunoglobulin Heavy Chains; Immunoglobulin alpha-Chains; Lymphoma; Mice; Molecular Weight; Nucleic Acid Hybridization; Protein Biosynthesis; RNA, Messenger; Transcription, Genetic


Immunology and Infectious Disease | Life Sciences | Medicine and Health Sciences


We have compared the synthesis and processing of immunoglobulin alpha chains in two murine cell lines, a B cell lymphoma that expresses membrane-bound IgA and a hybridoma that secretes IgA. Results of biosynthetic labeling experiments demonstrated that membrane-bound and secreted alpha chains have two distinct intracellular precursors, of different molecular weights and isoelectric points. RNAs from both of these cell lines direct the synthesis in vitro of two alpha polypeptides of Mr 59,000 and 62,000, the larger one being the precursor for membrane-bound alpha chain and the smaller one being the precursor for secreted alpha chain. These cell lines each contain three RNAs, 1.7, 2.1, and 3.1 kilobases in length, which hybridize with cDNA for the alpha constant region and which are present in different concentrations. Our results suggest that the smallest RNA encodes the secreted alpha chain and one or both of the larger RNAs encode(s) the membrane-bound alpha chain.


Proc Natl Acad Sci U S A. 1981 Oct;78(10):6436-40. Link to article on publisher's website

Journal/Book/Conference Title

Proceedings of the National Academy of Sciences of the United States of America


At the time of publication, Janet Stavnezer was not yet affiliated with the University of Massachusetts Medical School.

Related Resources

Link to article in PubMed

PubMed ID