T and B cell receptors discriminate major histocompatibility complex class II conformations influenced by the invariant chain

1992 ◽  
Vol 22 (8) ◽  
pp. 2121-2127 ◽  
Author(s):  
Satyajit Rath ◽  
Rong-Hwa Lin ◽  
Alexander Rudensky ◽  
Charles A. Janeway
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
B Cell ◽  
Class Ii ◽  
B Cell Receptors ◽  
Invariant Chain ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Cell Receptors ◽  
Histocompatibility Complex

scholarly journals Complex architecture of major histocompatibility complex class II promoters: reiterated motifs and conserved protein-protein interactions.

1996 ◽  
Vol 16 (9) ◽  
pp. 4683-4690 ◽  
Author(s):  
N Jabrane-Ferrat ◽  
J D Fontes ◽  
J M Boss ◽  
B M Peterlin
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
B Cell ◽  
Interferon Gamma ◽  
Class Ii ◽  
Inducible Expression ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Flanking Sequence ◽  
Histocompatibility Complex

The S box (also known as at the H, W, or Z box) is the 5'-most element of the conserved upstream sequences in promoters of major histocompatibility complex class II genes. It is important for their B-cell-specific and interferon gamma-inducible expression. In this study, we demonstrate that the S box represents a duplication of the downstream X box. First, RFX, which is composed of the RFX5-p36 heterodimer that binds to the X box, also binds to the S box and its 5'-flanking sequence. Second, NF-Y, which binds to the Y box and increases interactions between RFX and the X box, also increases the binding of RFX to the S box. Third, RFXs bound to S and X boxes interact with each other in a spatially constrained manner. Finally, we confirmed these protein-protein and protein-DNA interactions by expressing a hybrid RFX5-VP16 protein in cells. We conclude that RFX binds to S and X boxes and that complex interactions between RFX and NF-Y direct B-cell-specific and interferon gamma-inducible expression or major histocompatibility complex class II genes.

scholarly journals Related Leucine-based Cytoplasmic Targeting Signals in Invariant Chain and Major Histocompatibility Complex Class II Molecules Control Endocytic Presentation of Distinct Determinants in a Single Protein

1997 ◽  
Vol 185 (3) ◽  
pp. 429-438 ◽  
Author(s):  
Guangming Zhong ◽  
Paola Romagnoli ◽  
Ronald N. Germain
Keyword(s):  
Major Histocompatibility Complex ◽  
Major Histocompatibility Complex Class ◽  
Cytoplasmic Tail ◽  
Class Ii ◽  
Endocytic Pathway ◽  
Invariant Chain ◽  
Antigenic Peptides ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Histocompatibility Complex

Leucine-based signals in the cytoplasmic tail of invariant chain (Ii) control targeting of newly synthesized major histocompatibility complex class II molecules to the endocytic pathway for acquisition of antigenic peptides. Some protein determinants, however, do not require Ii for effective class II presentation, although endocytic processing is still necessary. Here we demonstrate that a dileucine-based signal in the cytoplasmic tail of the class II β chain is critical for this Ii-independent presentation. Elimination or mutation of this signal reduces the rate of re-entry of mature surface class II molecules into the endocytic pathway. Antigen presentation controlled by this signal does not require newly synthesized class II molecules and appears to involve determinants requiring only limited proteolysis for exposure, whereas the opposite is true for Ii-dependent determinants. This demonstrates that related leucine-based trafficking signals in Ii and class II control the functional presentation of protein determinants with distinct processing requirements, suggesting that the peptide binding sites of newly synthesized versus mature class II molecules are made available for antigen binding in distinct endocytic compartments under the control of these homologous cytoplasmic signals. This permits capture of protein fragments produced optimally under distinct conditions of pH and proteolytic activity.

B-cell control region at the 5' end of a major histocompatibility complex class II gene: sequences and factors

1988 ◽  
Vol 8 (10) ◽  
pp. 3975-3987
Author(s):  
A Dorn ◽  
H J Fehling ◽  
W Koch ◽  
M Le Meur ◽  
P Gerlinger ◽  
...  
Keyword(s):  
Major Histocompatibility Complex ◽  
B Cells ◽  
Major Histocompatibility Complex Class ◽  
B Cell ◽  
Simian Virus 40 ◽  
Class Ii ◽  
Immunoglobulin Gene ◽  
Complex Class ◽  
Major Histocompatibility ◽  
Histocompatibility Complex

Transcription of major histocompatibility complex class II genes is elaborately regulated. Mouse class II genes are transcribed primarily in B cells, peripheral macrophages and interdigitating cells, and thymic cortical and medullary cells. In this study, we began to identify the DNA sequences and protein factors that control expression of a class II gene in B cells, addressing in particular how closely they resemble those that regulate immunoglobulin gene expression. We describe a region upstream of the E alpha gene that is crucial for its transcription in the B cells of transgenic mice but is less important in cultured B-cell lines. The sequence of this region reveals several familiar motifs, including a second X-Y pair reminiscent of that residing in the promoter-proximal region of all class II genes, a B motif strikingly homologous to that associated with the immunoglobulin kappa gene enhancer, several Ephrussi motifs, and a Pu box-like sequence very similar to that implicated in simian virus 40 and lymphotrophic papovavirus expression in B cells. Careful study of the proteins that bind specifically to these different motifs prompts us to suggest that major histocompatibility complex class II and immunoglobulin genes rely on quite different factors to achieve B-cell-specific expression.

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