Lackner M R, Kornfeld K, Miller L M, Horvitz H R, Kim S K
Department of Developmental Biology, Stanford University Medical Center, California 94305.
Genes Dev. 1994 Jan;8(2):160-73. doi: 10.1101/gad.8.2.160.
During development of the Caenorhabditis elegans hermaphrodite, the gonadal anchor cell induces nearby Pn.p cells to adopt vulval fates. The response to this signal is mediated by a receptor tyrosine kinase signal transduction pathway that has been remarkably well conserved during metazoan evolution. Because mitogen-activated protein (MAP) kinases are activated by receptor tyrosine kinase pathways in vertebrate cells, we hypothesized that C. elegans MAP kinase homologs may play a role in vulval induction. Two C. elegans MAP kinase genes, mpk-1 and mpk-2 (mpk, MAP kinase), were cloned using degenerate oligonucleotide primers and PCR amplification; in parallel, genes involved in vulval induction were identified by screening for mutations that suppress the vulval defects caused by an activated let-60 ras gene. One such suppressor mutation is an allele of mpk-1. We used a new type of mosaic analysis to show that mpk-1 acts cell autonomously in the Pn.p cells. Our results show that mpk-1 plays an important functional role as an activator in ras-mediated cell signaling in vivo.
在秀丽隐杆线虫雌雄同体的发育过程中，性腺锚定细胞诱导附近的Pn.p细胞采用外阴命运。对该信号的反应由受体酪氨酸激酶信号转导途径介导，该途径在后生动物进化过程中得到了非常好的保守。由于丝裂原活化蛋白（MAP）激酶在脊椎动物细胞中被受体酪氨酸激酶途径激活，我们推测秀丽隐杆线虫MAP激酶同源物可能在外阴诱导中起作用。使用简并寡核苷酸引物和PCR扩增克隆了两个秀丽隐杆线虫MAP激酶基因mpk-1和mpk-2（mpk，MAP激酶）；同时，通过筛选抑制由激活的let-60 ras基因引起的外阴缺陷的突变来鉴定参与外阴诱导的基因。其中一个这样的抑制突变是mpk-1的一个等位基因。我们使用一种新型的镶嵌分析表明mpk-1在Pn.p细胞中自主发挥作用。我们的结果表明，mpk-1在体内作为ras介导的细胞信号传导中的激活剂发挥重要的功能作用。
