RnoALTD0031728-2/3 @ rn6

The authors describe here the identification and characterization of tumor necrosis factor receptor (TNFR)-associated factor 2A (TRAF2A), a splice variant of the TRAF2 molecule utilized for signal transduction by members of the TNFR family. TRAF2A and TRAF2 cDNAs are identical in sequence with the exception of an extra 21 base pairs of sequence encoding a 7-amino acid insert (via use of HsaALTD1017566-2/2) within the TRAF2A RING finger domain (TRAF2 uses HsaALTD1017566-1/2 instead). TRAF2A protein is capable of binding to the cytoplasmic domain of TNFR2 (p75) and is detectable in T-lymphoma cells stably transfected with the TRAF2A cDNA. Unlike TRAF2, TRAF2A has a short half-life ( approximately 100 min) in these cells and is expressed at only low levels in transiently transfected COS-7 cells. However, TRAF2A levels in transiently transfected COS-7 cells approach those of TRAF2 upon coexpression with TRAF1 and/or TRAF2, indicating that TRAF2A stability is regulated by the binding of other TRAF family proteins. Also in contrast to TRAF2, TRAF2A is unable to stimulate NF-kappaB activity when overexpressed in 293 cells and acts as a dominant inhibitor of TNFR2-dependent NF-kappaB activation.

TRAF 2A, a TRAF 2 splice variant with an altered ring finger (contains 7 additional amino acids (due to use of alternative splice site donor, HsaALTD1017566-2/2), is a specific activator of JNK, whereas TRAF2 (uses HsaALTD1017566-1/2) activates both NFkappa B and JNK pathways.