MADS盒(MADS box)是在转录因子家族中发现的一种高度保守的基序(motif)。可通过前四个家族成员MCM1、AGAMOUS、DEFICIENS和 SRF(serum response factor,血清反应因子)而加以识别。MADS得名于这四个成员的首字母缩写。
MADS盒基因是一类调节发育的重要基因,MADS-box基因的功能是保守的。已在所有真核生物中发现上百种MADS盒序列。MADS结构域蛋白可分为三种不同类型:MEF2型、ARG80型和植物类型MADS结构域蛋白。
在植物中,大多数MADS-box基因参与花发育的不同阶 段,相互之间可能形成复杂的复合物,并构成复杂的网络,决定花原基和花器官的特征,以及调节花发育的整个过程。此外,MADS盒基因还与植物营养生长、子 房发育、胚珠发育、种皮发育、根的形成、胚形态建成、共生诱导、愈伤组织分化、果实成熟、抗逆境有关。
The MADS box is a highly conserved sequence motif found in a family of transcription factors. The conserved domain was recognized after the first four members of the family, which were MCM1, AGAMOUS, DEFICIENS and SRF (serum response factor). The name MADS was constructed form the "initials" of these four "founders".
By now, more than hundred MADS box sequences have been found in species from all eukaryotic kingdoms. The family of MADS domain proteins has been subdivided into several distinct subfamilies. Most MADS domain factors play important roles in developmental processes. Most prominently, the MADS box genes in flowering plants are the "molecular architects" of flower morphogenesis.
All MADS-domain proteins known to date have additional domains attached to the C-terminus of the MADS-domain, and some also have N-terminal extensions. According to this overall structure, MADS-domain proteins can be subdivided into three different types, the MEF2 type, the ARG80 type and the plant type MADS-domain proteins. These three structural types are shown in the following sketch that shows an example of each type:
0 100 200 300 400
+-------------------+-------------------+-------------------+-------------------+
+--+-----------+------+------------------------------+
MCM1: | | MADS | SAM | |
+--+-----------+------+------------------------------+
+-----------+------+------------------------------------------------------+
MEF2B: | MADS | MEF2 | |
+-----------+------+------------------------------------------------------+
+-----------+-------+-----------+--------------+
DEF: | MADS | I | K | C |
+-----------+-------+-----------+--------------+
|<- MADS -->|
domain
|<-------- MIK domain --------->|
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