Abstract
We previously documented that a single BCL1 leukemia cell can produce μ and γ1 immunoglobulin heavy chains with identical variable segments in an allelically excluded fashion without heavy chain constant region gene rearrangement. To understand the mechanism of dual μ/γ1 synthesis in BCL1 subclones, we have analyzed mature and pre-RNA at the nascent and steady-state levels. We find μ and γ1 sequences linked in pre-RNA. However, the primary μ and γ1transcription units are about the same length (≈15 kilobases). Initiation of γ1 pre-RNA occurs upstream of Cγ1 at sites identical to those seen in lipopolysaccharide/interieukin-4-induced normal B cells. We propose that dual μ/γ1 RNA synthesis occurs by a discontinuous transcription mechanism involving either trans-splicing or ligation of μ pre-RNA initiated 5′ of the variable-diversity-joining region to γ1 pre-RNA initiated 5′ of Cγ1.
Original language | English (US) |
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Pages (from-to) | 1234-1238 |
Number of pages | 5 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 89 |
Issue number | 4 |
DOIs | |
State | Published - Feb 15 1992 |
Keywords
- Class switching
- Immunoglobulin gene regulation
- RNA processing
ASJC Scopus subject areas
- General