Ternary complex formation between the MADS-box proteins SQUAMOSA, DEFICIENS and GLOBOSA is involved in the control of floral architecture in Antirrhinum majus.
In Antirrhinum, floral meristems are established by meristem identity genes. Floral meristems give rise to floral organs in whorls, with their identity established by combinatorial activities of organ identity genes. Double mutants of the floral meristem identity gene SQUAMOSA and organ identity genes DEFICIENS or GLOBOSA produce flowers in which whorled patterning is partially lost. In yeast, SQUA, DEF and GLO proteins form ternary complexes via their C-termini, which in gel-shift assays show increased DNA binding to CArG motifs compared with DEF/GLO heterodimers or SQUA/SQUA homodimers. Formation of ternary complexes by plant MADS-box factors increases the complexity of their regulatory functions and might be the molecular basis for establishment of whorled phyllotaxis and combinatorial interactions of floral organ identity genes.
Egea-Cortines
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Max-Planck-Institut für Züchtungsforschung, Carl-von-Linne Weg 10, 50829 Köln, Germany. Marcos.Egea@etsia.upct.es
Saedler
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Sommer
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D001483:Base Sequence; D026281:DEFICIENS Protein; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010944:Plants / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism
D026281:DEFICIENS Protein; D017931:DNA Primers; D004268:DNA-Binding Proteins; C102172:GLOBOSA protein, plant; D018398:Homeodomain Proteins; D010940:Plant Proteins; C074081:SQUA protein, Antirrhinum majus