Cell adhesion receptors inC. elegans

Control ofC. eleganshermaphrodite gonad size and shape byvab-3/Pax6-mediated regulation of integrin receptors

“…C. elegans ␣ integrin pat-2 is somewhat more homologous to mammalian ␣5 than to other vertebrate ␣ subunits (Cox et al 2004). Since pat-2 expression in DTCs has not been reported, we examined DTCs in three independent transgenic lines generated with a transcriptional fusion containing 6 kb of pat-2 upstream sequence linked to GFP.…”

“…However, detailed in vivo analyses of integrins in migration are complicated by embryonic lethality of integrin-null mutants and by pleiotropic, redundant, or overlapping functions among the 18 ␣ and eight ␤ chains in mammals. Some of the experimental constraints inherent in studies on mice can be bypassed by using the nematode Caenorhabditis elegans, which has two conserved integrin receptors composed of an ina-1/␣ or pat-2/␣ subunit associated with the pat-3/␤ integrin subunit (Cox et al 2004).Post-embryonic gonadogenesis in C. elegans provides an excellent model of cell migration during development. The shape of the hermaphrodite gonad is dictated by migration of two leader cells called the distal tip cells (DTCs) (Hubbard and Greenstein 2000).…”

“…However, detailed in vivo analyses of integrins in migration are complicated by embryonic lethality of integrin-null mutants and by pleiotropic, redundant, or overlapping functions among the 18 ␣ and eight ␤ chains in mammals. Some of the experimental constraints inherent in studies on mice can be bypassed by using the nematode Caenorhabditis elegans, which has two conserved integrin receptors composed of an ina-1/␣ or pat-2/␣ subunit associated with the pat-3/␤ integrin subunit (Cox et al 2004).…”

Adherens Junction: Molecular Architecture and Regulation

“…The functional importance of AJs also differs among species. For example, Caenorhabditis elegans has a classic-cadherin-type molecule (HMR-1), but its role in cell junction formation is limited: HMR-1-deficient animals fail to enclose the epidermal sheets, but their general cell junctions look normal even in the absence of this cadherin (Cox et al 2004). The organization of apical junctional complexes is also different between vertebrates and invertebrates.…”

“…The carboxy-terminal half of the cytoplasmic domain, on the other hand, binds b-catenin or plakoglobin (g-catenin), which are close relatives of each other (Ozawa et al 1989;Knudsen and Wheelock 1992;Ozawa and Kemler 1992). As mentioned above, these molecular partners for the cytoplasmic domain are well conserved among different animal species; e.g., its invertebrate versions can bind both p120-catenin (JAC-1 in C. elegans) and b-catenin (Armadillo in Drosophila; HMP-2 in C. elegans) (Peifer and Wieschaus 1990;Cox et al 2004). These catenins in turn associate with a variety of other molecules, including cytoskeletal proteins and their regulators.…”