PlantTFDB
PlantRegMap/PlantTFDB v5.0
Plant Transcription Factor Database
Previous version: v3.0 v4.0
Pyrus communis
MIKC_MADS Family
Species TF ID Description
PCP001807.1MIKC_MADS family protein
PCP001808.1MIKC_MADS family protein
PCP002223.1MIKC_MADS family protein
PCP002224.1MIKC_MADS family protein
PCP002331.1MIKC_MADS family protein
PCP002673.1MIKC_MADS family protein
PCP004454.1MIKC_MADS family protein
PCP005825.1MIKC_MADS family protein
PCP006149.1MIKC_MADS family protein
PCP006918.1MIKC_MADS family protein
PCP007521.1MIKC_MADS family protein
PCP012204.1MIKC_MADS family protein
PCP013106.1MIKC_MADS family protein
PCP013107.1MIKC_MADS family protein
PCP013543.1MIKC_MADS family protein
PCP014073.1MIKC_MADS family protein
PCP014552.1MIKC_MADS family protein
PCP018702.1MIKC_MADS family protein
PCP020055.1MIKC_MADS family protein
PCP021413.1MIKC_MADS family protein
PCP022302.1MIKC_MADS family protein
PCP022935.1MIKC_MADS family protein
PCP022936.1MIKC_MADS family protein
PCP023681.1MIKC_MADS family protein
PCP024843.1MIKC_MADS family protein
PCP030812.1MIKC_MADS family protein
PCP031198.1MIKC_MADS family protein
PCP031532.1MIKC_MADS family protein
PCP032175.1MIKC_MADS family protein
PCP032215.1MIKC_MADS family protein
PCP032233.1MIKC_MADS family protein
PCP032236.1MIKC_MADS family protein
PCP035343.1MIKC_MADS family protein
PCP038145.1MIKC_MADS family protein
PCP042878.1MIKC_MADS family protein
PCP044772.1MIKC_MADS family protein
PCP044935.1MIKC_MADS family protein
MIKC_MADS (MIKC-type MADS) Family Introduction

The best studied plant MADS-box transcription factors are those involved in floral organ identity determination. Analysis of homeotic floral mutants resulted in the formulation of a genetic model, named the ABC model, that explains how the combined functions of three classes of genes (A, B, and C) determine the identity of the four flower organs (reviewed by Coen and Meyerowitz, 1991). Arabidopsis has two A-class genes (AP1 and AP2 [Bowman et al., 1989]), two B-class genes (PI and AP3), and a single C-class gene (AG), of which only AP2 is not a MADS-box gene. Recently, it was shown that the Arabidopsis B- and C-function genes, which control petal, stamen, and carpel development, are functionally dependent on three highly similar MADS-box genes, SEP1, SEP2, and SEP3 (Pelaz et al., 2000). Interestingly, only when mutant knockout alleles of the three SEP genes were combined in a triple sep1 sep2 sep3 mutant was loss of petal, stamen, and carpel identity observed, resulting in a flower composed of only sepals. This example shows that redundancy occurs in the MADS-box gene family, which complicates reverse genetic strategies for gene function analysis. The SHP genes provide another example of MADS-box gene redundancy. shp1 and shp2 single mutants do not exhibit any phenotypic effect, whereas in the double mutant, development of the dehiscence zone is disturbed in the fruit, resulting in a failure to release seeds (Liljegren et al., 2000)[1].

It has been proposed that there are at least 2 lineages (type I and type II) of MADS-box genes in plants, animals, and fungi. Most of the well-studied plant genes are type II genes and have three more domains than type I genes from the N to the C terminus of the protein:intervening (I) domain (~30 codons), keratin-lik e coiled-coil (K) domain (~70 codons), and Cterminal (C) domain (variable length). These genes are called the MIKC-type and are specific to plants[2].

The MADS-box is a DNA binding domain of 58 amino acids that binds DNA at consensus recognition sequences known as CArG boxes [CC(A/T)6GG] (Hayes et al., 1988; Riechmann et al., 1996b). The interaction with DNA has been studied in detail for the human and yeast MADS-box proteins thanks to the resolved crystal structures (Pellegrini et al., 1995; Santelli and Richmond, 2000). The I domain is less conserved and contributes to the specification of dimerization. The K domain is characterized by a coiled-coil structure, which facilitates the dimerization of MADS-box proteins (Davies et al., 1996; Fan et al., 1997). The C domain is the least conserved domain; in some cases, it has been shown to contain a transactivation domain or to contribute to the formation of multimeric MADS-box protein complexes (Egea-Cortines et al., 1999; Honma and Goto, 2001)[1].

1.Parenicova L, de Folter S, Kieffer M, Horner DS, Favalli C, Busscher J, Cook HE, Ingram RM, Kater MM, Davies B, Angenent GC, Colombo L.
Molecular and phylogenetic analyses of the complete MADS-box transcription factor family in Arabidopsis: new openings to the MADS world.
Plant Cell. 2003 Jul;15(7):1538-51.
PMID: 12837945
2.Nam J, dePamphilis CW, Ma H, Nei M.
Antiquity and evolution of the MADS-box gene family controlling flower development in plants.
Mol Biol Evol. 2003 Sep;20(9):1435-47. Epub 2003 May 30.
PMID: 12777513