CITED2 regulates MMP-1 through specific motif. A, B) Effect of transfecting chondrocytes with plasmids encoding either WT CITED2, or CITED2 deleted, truncated, or point mutants on MMP-1 and CITED2 mRNA (PCR; A) and/or protein (Western blot) expression in the presence of IL-1β (B). CR, conserved region; Δsrj, CITED2 WT with deletion of 39-aa serine-glycine rich junction; EPEE, mutated LPEL (aa 243–246) motif. C, D) Effect of cotransfecting WT Ets-1 or Ets-1 deleted or truncated mutants with CITED2 (C) on MMP-1 and CITED2 mRNA (PCR) and/or protein (Western blot) expression (D) in the presence of IL-1β.