ABSTRACT
<p><b>OBJECTIVE</b>To explore the interaction between SerpinB5 and MAFbx in gastric cancer cell and to identify the interaction sites.</p><p><b>METHODS</b>The interaction between SerpinB5 and MAFbx was screened and validated by yeast two-hybrid screening and co-immunoprecipitation. The expression of MAFbx was analyzed after SerpinB5 expression being modified by RNA interference and pGBKT7-SerpinB5 transfection. The impact of SerpinB5 on the expression of MAFbx was studied in gastric cancer cell line SUN-16. A model of MAFbx was constructed by homology modeling. The related residues for interaction were analyzed by Autodock4.0.</p><p><b>RESULTS</b>The interaction between SerpinB5 and MAFbx was validated. The expression of MAFbx changed along with SerpinB5 expression. Amino acids including PRO261, ASN361, and LYS362 were key residue in the interaction of SerpinB5 and MAFbx.</p><p><b>CONCLUSION</b>SerpinB5 interacts with MAFbx in gastric cancer cell. Amino acids including PRO261, ASN361, and LYS362 are potential binding sites.</p>