Extracellular proteins needed for C-elegans mechanosensation
Extracellular proteins needed for C-elegans mechanosensation
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DOI：
10.1016/s0896-6273(00)80035-5
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发表时间：
1996-01-01
期刊：
影响因子：
16.2
通讯作者：
Chalfie, M
中科院分区：
文献类型：
--
作者：
Du, HP;Gu, GQ;Chalfie, M
mec-5和mec-9基因编码假定的细胞外蛋白，这些蛋白允许C.优雅的人对温柔的触摸有反应。MEC-5是一种胶原蛋白，由触觉细胞周围的表皮细胞制成。导致触觉不敏感的突变会影响这种胶原蛋白的Gly-X-Y重复序列。mec-9产生两种转录物，其中较大的一种在触觉细胞和两种PVD神经元中表达。该转录本编码具有5个Kunitz型蛋白酶抑制剂结构域、6个EGF样重复序列（2个Ca 2+结合型）和一个富含谷氨酸的区域的蛋白质。导致触摸不敏感的错义突变影响EGF样和Kunitz结构域。由于mec-9功能丧失突变主要增强几种mec-5突变的触摸不敏感表型，因此MEC-5和MEC-9可能相互作用。我们认为这些蛋白质为触觉细胞的机械感觉通道提供了一个细胞外附着点。
The mec-5 and mec-9 genes encode putative extracellular proteins that allow a set of six touch receptor neurons in C. elegans to respond to gentle touch. MEC-5 is a collagen made by the epidermal cells that surround the touch cells. Mutations causing touch insensitivity affect the Gly-X-Y repeats of this collagen. mec-9 produces two transcripts, the larger of which is expressed in the touch cells and two PVD neurons. This transcript encodes a protein with 5 Kunitz-type protease inhibitor domains, 6 EGF-like repeats (2 of the Ca2+-binding type), and a glutamic acid-rich region. Missense mutations causing touch insensitivity affect both the EGF-like and Kunitz domains. Since mec-9 loss of function mutations dominantly enhance the touch insensitive phenotype of several mec-5 mutations, MEC-5 and MEC-9 may interact. We propose that these proteins provide an extracellular attachment point for the mechanosensory channels of the touch cells.