passages.id: split_1_test_2724_passage
passages.type: progene_text
passages.text: Cross - linking of CD158j resulted in selective phosphorylation of c-Jun NH(2) - terminal protein kinase ( JNK ) and its upstream kinase , MKK4 that led to the expression of ATF-2 and c-Jun , all in the absence of extracellular signal - regulated kinase ( ERK ) 1 / 2 phosphorylation .