UNC112. A new regulator of cell-extracellular matrix adhesions?
UNC112. A new regulator of cell-extracellular matrix adhesions?
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UNC112。
DOI：
10.1083/jcb.150.1.f9
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Schaller,MD
中科院分区：
文献类型：
--
作者：
Schaller,MD
Genetic analyses of Drosophila and Caenorhabditis elegans have yielded invaluable insights into many basic biological processes, perhaps most notably in the fields of receptor tyrosine kinase signaling and apoptosis. In this issue of The Journal of Cell Biology, the identification of UNC-112 as a new cytoskeletal component that may function in the assembly of cell–extracellular matrix adhesions in the muscle of C. elegans is described (Rogalski et al., 2000). Since the components of dense bodies of the C. elegans muscle are similar to the components of focal adhesions in non-muscle cells, this finding may have broader implications for the assembly of cell–extracellular matrix adhesions.In non-muscle cells, the assembly of focal adhesions has been extensively analyzed using mammalian fibroblasts. The integrins, which are transmembrane heterodimers, are major components of focal adhesions (Burridge and Chrzanowska-Wodnicka, 1996; Jockusch et al., 1995). In addition, cytoskeletal proteins such as vinculin and talin are localized at these sites. The integrins must engage their extracellular matrix ligands to form focal adhesions. In addition, the cytoplasmic domains of the integrins are important for focal adhesion localization, the tail of the ß subunit promoting localization and the tail of the α subunit regulating focal adhesion localization (Burridge and Chrzanowska-Wodnicka, 1996). Cytoplasmic signals, most importantly Rho-mediated contractility, are required for the assembly of focal adhesions in fibroblasts (Schoenwaelder and Burridge, 1999). Finally, one very interesting property of integrins that may be relevant for the formation of these structures is inside-out signaling, a process where cytoplasmic signals act to modulate the affinity of the integrins for their extracellular ligands (Hughes and Pfaff, 1998). In C. elegans, genetic and cell biological approaches have been applied to study the assembly of cell–extracellular matrix adhesions in the muscle of the embryo. Following gastrulation, the embryo elongates to form a worm before hatching. Due to the space constraint of the eggshell, the embryo folds back upon itself twice during the elongation process to form the two-and threefold stages of embryogenesis. Embryonic movement initiates before the twofold stage. Body movements of both the embryo and adult are controlled by four strips of striated muscle, each of which are two cells wide and one cell thick, that lie im-
