The cytoplasmic and transmembrane domains of MHC class II beta chains deliver distinct signals required for MHC class II-mediated B cell activation.
Class II-mediated signals play potential roles in B cell activation and antigen presentation. The regions of the class II molecule participating in B cell signaling are incompletely defined. Our prior analysis of structural requirements of the cytoplasmic domain of A beta revealed that only the eight membrane-proximal residues are required for signaling. Here, we report that the sequence and position of two of these are critical, and present direct evidence that the A beta transmembrane domain is also involved in signaling, via a pathway distinct from the cytoplasmic domain. These results demonstrate that specific regions in both the cytoplasmic and transmembrane domains of the class II molecule have distinct signaling functions.
Harton
J A
JA
Department of Microbiology, University of Iowa, Iowa City 52242, USA.
Van Hagen
A E
AE
Bishop
G A
GA
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D000242:Cyclic AMP / Q000096:biosynthesis; D000949:Histocompatibility Antigens Class II / Q000737:chemistry / Q000502:physiology*; D008213:Lymphocyte Activation; D051379:Mice; D008969:Molecular Sequence Data; D013329:Structure-Activity Relationship; D014162:Transfection
D000949:Histocompatibility Antigens Class II; D000242:Cyclic AMP