Dimerization specificity of Arabidopsis MADS domain homeotic proteins APETALA1, APETALA3, PISTILLATA, and AGAMOUS.

• DOI: 10.1073/pnas.93.10.4793
• Publication Date: 2002-07-26T14:34:16Z
• Authors: J L Riechmann; B A Krizek; E M Meyerowitz
• Keywords: Agamous; MADS-box

The MADS domain homeotic proteins APETALA1 (AP1), APETALA3 (AP3), PISTILLATA (PI), and AGAMOUS (AG) act in a combinatorial manner to specify the identity of Arabidopsis floral organs. molecular basis for this mode action was investigated. Immunoprecipitation experiments indicate that all four are capable interacting with each other. However, these exhibit "partner-specificity" formation DNA-binding dimers; only AP1 homodimers, AG AP3/PI heterodimers binding CArG-box sequences. Both heterodimer or homodimers formed when three corresponding present together. use chimeric by swapping indicates L region (which follows box) constitutes key determinant selective dimers. implications results ABC genetic model flower development discussed.