E-cadherin (epithelial-cadherin), also known as cadherin-1 (CADH1), is a calcium-dependent adherens junction protein that forms homophilic intercellular contacts in epithelial cells []. It is essential for embryonic development in mice []. It cooperates with N-cadherin during lensdevelopment [].
This domain can be found in chromodomain helicase DNA-binding protein 1 (Chd1) present in Saccharomyces cerevisiae. Cdh1 proteins have been associated with the efficient assembly and spacing of nucleosomes []. Chd1 consists of a double chromodomain, an Snf2-related ATPase domain and a C-terminal DNA binding domain [, ].This domain comprises the first four helices of the Chd1 DNA binding domain, which can be divided into regions SANT, HL1 and the β-linker. The HL1 region comprises of some 40 residues specific to budding yeast that are unlikely to form such a prominent feature or perform a conserved function in other species. Basic residues on the alpha-1 helix are thought to be important for DNA interaction [].This domain is also found in the Hrp3 protein, another member of the Cdh1 family in Schizosaccharomyces pombe. Like Cdh1, Hrp3 also comprises two chromo-domains, SNF2-like ATPase/7 helicase domains, and a C-terminal DNA binding domain [].
CDH1 is an ATP-dependent chromatin-remodelling factor and plays an important role in regulating nucleosome assembly and mobilization. CHD1 consists of double chromodomain, SNF2-related ATPase domain, and a C-terminal DNA-binding domain. The DNA-binding domain contains SANT (Swi3, Ada2, N-CoR, TFIIIB) and SLIDE (SANT-like ISWI) domains in its C-terminal region []. SANT domains are structurally related to Myb-like domains are common motifs found in chromatin interacting proteins. Deletion of individual SANT or SLIDE domains in CDH1 does not significantly affect nucleosome binding, but combined deletion of both domains severely compromise binding, suggesting that the SANT-SLIDE motif recognizes DNA/nucleosomes as a single cooperative unit. SANT sequences of Chd1 proteins are the most distantly relation group of sequences relation to other SANT/Myb sequences, and are more diverse than other SANT proteins []. The SANT and SLIDE regions are well conserved in both Chd1 and ISWI (imitation switch) remodelling enzymes []. This domain comprises the SANT region and the helical linker region 1 (HL1).
The anaphase promoting complex/cyclosome (APC/C) is a cell cycle-regulated E3 ubiquitin ligase that controls progression through mitosis and the G1 phase of the cell cycle. The APC/C consists of thirteen different subunits and, in somatic cells, has two co-activators: Cdc20 and Cdh1 (also known as Fzr1), which associate with the APC/C core at defined stages of the cell cycle. APC/C is only active between metaphase and the end of the next G1 phase. During this time, APC/CCdc20 initiates anaphase and mitotic exit,while APC/CCdh1 contributes to mitotic exit and establishment of a stable G1 state []. This entry represents the APC/C subunit 16 [].
The anaphase promoting complex/cyclosome (APC/C) is a multisubunit ubiquitin ligase that targets mitotic regulators for degradation in exit from mitosis. At the end of mitosis, APC/C is activated by phosphorylation and association with the WD-40 protein Cdc20/Fizzy []. The inhibitory phosphorylation of Cdc20/Fizzy may have a role as a safeguard to keep the cyclosome inactive in early mitosis and under conditions of mitotic checkpoint arrest []. This entry includes Cdc20/Fizzy homologues from fungi, plants and animals.Three characterised budding yeasts homologues are included in this entry: Cdc20, Cdh1 and Ama1. Cdc20 and Cdh1 have been shown to activate APC/C during mitosis, while Ama1 is a meiosis-specific activator of the APC/C []. The APC/C-Cdh1 is also found involved in the cellular response to DNA damage []. Protein cortex from Drosophila melanogasterwhich is a female meiosis-specific activator of the anaphase promoting complex/cyclosome (APC/C) required for the completion of meiosis in oocytes, is also included in this entry. Cortex activates the ubiquitin ligase activity and substrate specificity of APC/C and triggers the sequential degradation of mitotic cyclins in meiosis [, ].
