| Id |
Subject |
Object |
Predicate |
Lexical cue |
| S1 |
0-127 |
Sentence |
denotes |
A factor known to bind to endogenous Ig heavy chain enhancer only in lymphocytes is a ubiquitously active transcription factor. |
| S2 |
128-312 |
Sentence |
denotes |
The transcriptional enhancer located in the first intron of the immunoglobulin heavy chain constant region is a major determinant of B-cell-specific expression of immunoglobulin genes. |
| S3 |
313-443 |
Sentence |
denotes |
Like other enhancers, the Ig heavy chain enhancer contains several short sequence motifs that bind specific transcription factors. |
| S4 |
444-580 |
Sentence |
denotes |
Each binding site contributes to the overall activity of the enhancer, however no single element seems absolutely required for activity. |
| S5 |
581-708 |
Sentence |
denotes |
For a better understanding of the Ig heavy chain enhancer components, we have cloned and analyzed individual sequence elements. |
| S6 |
709-817 |
Sentence |
denotes |
We find that the factor that binds to the E3 enhancer motif, CATGTGGC, is a ubiquitous transcription factor. |
| S7 |
818-952 |
Sentence |
denotes |
It is present in an active form in both B cells and non-B cells, where it can mediate transcriptional activation in vitro and in vivo. |
| S8 |
953-1300 |
Sentence |
denotes |
However, despite its ability to activate transcription of a transfected reporter gene, the factor is apparently unable to bind to the endogenous Ig heavy chain enhancer in non-lymphoid cells: In previous experiments by others, the characteristic in vivo footprint of this factor, designated NF-muE3, was detected in B cells but not in non-B cells. |
| S9 |
1301-1797 |
Sentence |
denotes |
From this and other findings the picture emerges that there are at least three categories of factors which mediate cell-type-specific transcription in B lymphocytes: (a) cell-specific factors such as Oct-2A and Oct-2B that are not expressed in most other cell types: (b) ubiquitous factors such as NF-kappa B that are constitutively active in B cells but are sequestered in an inactive form in other cells; (c) ubiquitously active factors, exemplified by the one binding to the E3 sequence motif. |
| S10 |
1798-2037 |
Sentence |
denotes |
This factor is present in an active form in a variety of cell types but is apparently unable to bind to the endogenous Ig heavy chain enhancer in non-B cells, perhaps due to a non-permissive chromatin structure of the Ig heavy chain locus. |
