Mullins Mary C
Department of Cell and Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
Dev Cell. 2006 Feb;10(2):154-6. doi: 10.1016/j.devcel.2006.01.009.
The enigma of Sizzled, a secreted Frizzled-related protein, has been resolved in a recent study from the De Robertis lab ( [in the January 13 issue of Cell]). Sizzled, although homologous to other Wnt antagonists, does not function as such, nor does it function within a Wnt signaling pathway. Remarkably it functions as an antagonist of BMP signaling, competing with Chordin for binding to its inhibitor a Tolloid-related metalloprotease. This competition protects Chordin from cleavage, thus allowing it to bind and limit BMP signaling.
分泌型卷曲相关蛋白Sizzled之谜，已在德罗伯特斯实验室最近的一项研究中（发表于1月13日的《细胞》杂志）得以破解。Sizzled虽然与其他Wnt拮抗剂同源，但其并非作为Wnt拮抗剂发挥作用，也不在Wnt信号通路中起作用。值得注意的是，它作为BMP信号的拮抗剂发挥作用，与脊索蛋白竞争结合其抑制剂——一种类原肠胚形成蛋白相关金属蛋白酶。这种竞争保护了脊索蛋白不被裂解，从而使其能够结合并限制BMP信号。
