Transcription regulatory networks in Caenorhabditis elegans

2RSSE.1 encodes a protein that contains a RhoGAP domain and that is similar to Drosophila RhoGAP71E whose activity regulates the number and guidance of mushroom body axons.

aat-4 encodes a predicted amino acid transporter catalytic subunit; unlike catalytic subunits in other organisms, however, AAT-4 does not contain the highly conserved cysteine residue known to facilitate covalent interaction with a glycoprotein subunit, suggesting that AAT-4 does not require this residue for heterodimer formation or, alternatively, does not require the glycoprotein subunit for function.

aat-9 encodes an amino acid transporter catalytic subunit; AAT-9 lacks the conserved cysteine residue proposed to be essential for association with a glycoprotein subunit, and when expressed alone in Xenopus ooctyes, AAT-9 can localize to the cell surface and function as an aromatic amino acid exchanger that displays substrate-activated anion conductance; nevertheless, AAT-9 activity is enhanced by co-expression with the ATG-1 and ATG-2 glycoprotein subunits; an aat-9::gfp promoter fusion directs expression in anterior neurons, including some chemosensory neurons, as well as in some anterior body wall muscles.

abl-1 encodes, by alternative splicing, three isoforms of a Src homology (SH) 2 and 3 domain-containing non-receptor tyrosine kinase orthologous to human ABL1 (OMIM:189980, mutated in chronic myeloid leukemia) and ABL2 (OMIM:164690); ABL-1 inhibits germline apoptosis induced by radiation or by natural aging, but it has no effect on apoptosis induced by starvation or by chemical mutagens (ethylnitrosourea, ethylmethanesulfonate, cisplatin, etoposide), or on constitutive ('physiological') germline apoptosis; at the same time, ABL-1 is required for germline apoptosis induced by oxidative, osmotic or heat-shock stress, and is also required for pathogenesis by Shigella flexneri infecting the intestine; ABL-1-inhibited apoptosis is confined to a single gonad arm undergoing radiation, having no nonautonomous effect on the unirradiated arm; abl-1 is expressed in the germline, in most or all cells of early embryos, and in postembryonic pharynx, tail ganglia and ventral nerve cord; abl-1(ok171) mutants are hypersensitive to germline apoptosis and resistant to S. flexneri infection; both abl-1(ok171) phenotypes are phenocopied by c-ABL inhibitors such as STI-571 (Gleevec); ABL-1-inhibited apoptosis requires active CED-3 and EGL-1, inactive CED-9, and active AKT-1, CEP-1, CLK-1, HUS-1, and MRT-2; abl-1(ok171) has no effect on somatic apoptosis, and abl-1(ok171) mutants are generally normal; abl-1 transcripts are enriched in cultured unc-4::GFP neurons.

abt-5 encodes a predicted ATP-binding cassette (ABC) transporter that is a member of the ABCA subfamily of transport proteins; ABT-5 is predicted to function as a transmembrane protein that couples energy to transport of various molecules across membranes, but as loss of abt-5 activity via RNAi results in no obvious defects, the precise role of abt-5 in C. elegans development and/or behavior is not yet known; abt-5 promoter-gfp fusion proteins are expressed in larvae and adults in the intestine and in unidentified cells in the head.

abts-3 encodes an anion transporter; abts-3 promoter gfp fusions are expressed in neurons and hypodermal cells in a pattern coincident with abts-1.

abu-11 encodes a transmembrane protein with a predicted signal sequence, a glutamine/asparagine-rich domain and multiple cysteine-rich repeats (DUF139); abu-11 expression is induced by blockage of the unfolded-protein response in the endoplasmic reticulum, and ABU-11 may help protect the organism from damage by improperly folded nascent protein.