Sander V, Müllegger J, Lepperdinger G
Austrian Academy of Sciences, Institute of Molecular Biology, Billrothstrasse 11 A-5020, Salzburg, Austria.
Mech Dev. 2001 Apr;102(1-2):251-3. doi: 10.1016/s0925-4773(01)00302-1.
A complete cDNA encoding the Xenopus laevis homologue of the aggrecan/versican family member, brevican (Xbcan) was cloned from an embryonic stage 42 cDNA library. In the deduced amino acid sequence, 1152 in length, similarity to the hyaluronan-binding (link) domains of brevicans from other species were present in the N-terminal region as well as EGF-, lectin- and complement regulatory protein-like domains in the C-terminal part, the latter three being characteristic for brevican found within the extracellular matrix (J. Biol. Chem. 269 (1994) 10119). Indeed, Xbcan was secreted into the extracellular space as a soluble protein when expressed in oocytes. No cDNAs encoding a GPI-anchored bcan variant could be isolated from that cDNA library. During embryonic development, the expression of this gene was first observed in the notochord of neurula stage embryos. In addition to this, in tailbuds, Xbcan was also found to be expressed within the fifth and sixth rhombomere of the hindbrain. In tadpole stage embryos, expression was furthermore observed in periventricular regions of the developing brain and the rostral part of the spinal cord.
从非洲爪蟾胚胎42期的cDNA文库中克隆出了一个完整的编码聚集蛋白聚糖/多功能蛋白聚糖家族成员短蛋白聚糖（Xbcan）的非洲爪蟾同源物的cDNA。在推导的长度为1152个氨基酸的序列中，N端区域存在与其他物种短蛋白聚糖的透明质酸结合（连接）结构域相似的结构域，C端部分存在表皮生长因子（EGF）样、凝集素样和补体调节蛋白样结构域，后三个结构域是细胞外基质中短蛋白聚糖的特征性结构域（《生物化学杂志》269 (1994) 10119）。实际上，Xbcan在卵母细胞中表达时以可溶性蛋白的形式分泌到细胞外空间。从该cDNA文库中未分离到编码糖基磷脂酰肌醇（GPI）锚定的bcan变体的cDNA。在胚胎发育过程中，该基因的表达首先在神经胚期胚胎的脊索中被观察到。除此之外，在尾芽中，还发现Xbcan在后脑的第五和第六菱脑节中表达。在蝌蚪期胚胎中，在发育中的脑的脑室周围区域和脊髓的前端也观察到了表达。
