Domain families pathway

The situation with the domain families of the ubiquitin-mediated pathway contrasts with the domain families that function in animal and plant programmed cell death, or apoptosis. As reviewed elsewhere (Ara-vind et al., 1999b), a few domains in eukaryotic apoptotic proteins have prokaryotic homologs, including the cysteine protease family of caspases... 

The four mammalian ARs are members of the rhodopsin-like Class A family of GPCRs, which contain seven transmembrane helical domains ( TMs). Character istics of the four subtypes of the human ARs, length of their primary sequences, their chromosomal localization, and their signaling pathways are given in Table 1. The A2a receptor is considerably longer than the other three subtypes, due to its extended carboxy-terminal. 

BH3 domain) of the BH3-only proteins binds to other Bcl-2 family members thereby influencing their conformation. This interaction facilitates the release of cytochrome C and other mitochondrial proteins from the intermembrane space of mitochondria. Despite much effort the exact biochemical mechanism which governs this release is not yet fully understood. The release of cytochrome C facilitates the formation of the apoptosome, the second platform for apoptosis initiation besides the DISC. At the apoptosome which is also a multi-protein complex the initiator caspase-9 is activated. At this point the two pathways converge. 

The thiazide sensitive NaCI cotransporter (NCC) is the major pathway of NaCI entry in the distal convoluted tubule. Like NKCC2, NCC contains 12 putative transmembrane domains and long intracellular amino-and carboxy-tails. NCC and NKCC as well as the KC1 cotransporter KCC are members of the same gene family and have considerable homology. 

For all other members of the TRP family it still has to be shown whether the presumptive pore loop or other protein domains actually line the ion conducting pathway of the channel. Based on the results showing that expression of most TRPC channels yields currents carried by Na+and Ca2+, and that expression of TRPM4 and TRPM7 channels yields currents carried by Na+ but not by Ca2+(TRPM4) or even currents carried by Mg2+or Ca2+(TRPM7), it seems likely that the pore structures of these channel proteins vary considerably. 

In addition to Lyn, a second Src family kinase, Fyn, associates with the FceRI P chain and is activated after FceRI aggregation [26]. Fyn phosphorylates the adaptor Gab2 to activate the phosphatidyUnositol-3-OH kinase (PI3K) pathway the SH2 domain-... 

Figure 11.2 Biosynthesis of the nine-membered enediynes. Members of this family share a common biosynthetic pathway for the enediyne core intermediate. Domains are shown in circles with abbreviations (KS, ketosynthase AT, acyltransferase KR, ketoreductase DH, dehydratase TE, thioesterase ACP, acyl carrier protein PPT, phosphopantetheine transferase)...

---