sma-9 encodes, by extensive alternative splicing, at least 13 isoforms, a number of which are large (~2000-residue) proteins with at least three N-terminal involucrin domains, seven C-terminal zinc-finger domains, and a glutamine/asparagine-rich domain; SMA-9 is orthologous to the Drosophila Smad cofactor Schnurri (FBgn0003396) and the vertebrate HIVEP proteins (Human Immunodeficiency Virus Type 1 Enhancer-Binding Proteins, OMIM:194540, OMIM:143054, and OMIM:606649); in C. elegans, sma-9 functions in a subset of the TGF-beta-mediated signaling pathways that regulate body size and male tail patterning and morphogenesis; sma-9, through this pathway, also regulates reproductive aging; studies have shown that a reduction of TGF-beta pathway genes extends reproductive span by maintaining oocyte and germline quality; sma-9 also functions antagonistically to the TGF-beta signaling pathway, and in parallel to the lin-12/Notch pathway, to effect proper cell fate specification in the postembryonic mesodermal lineage, the M lineage; SMA-9 is widely expressed and localizes to nuclei.
Enables transcription coactivator activity and transcription corepressor activity. Involved in several processes, including determination of adult lifespan; nematode male tail tip morphogenesis; and regulation of gene expression. Acts upstream of or within cellular response to heat. Located in nucleus. Expressed in several structures, including excretory cell; intestine; spermatheca; ventral cord neurons; and vulva. Used to study Alzheimer's disease. Human ortholog(s) of this gene implicated in autosomal dominant intellectual developmental disorder 43. Is an ortholog of human HIVEP1 (HIVEP zinc finger 1); HIVEP2 (HIVEP zinc finger 2); and HIVEP3 (HIVEP zinc finger 3).