Abstract\n\n Many eukaryotes possess two types of spliceosomes: the U2-dependent and U12-dependent spliceosomes. The U2-dependent spliceosome processes more than 99% of all introns, whereas the U12-dependent spliceosome acts on only about 0.3% of introns, one-third of which start with AT and end with AC, with the remainder having GT\u2013AG termini. How the U12-dependent spliceosome splices two types of introns with different terminal sequences remains poorly understood. Human CENATAC is a subunit of the U12-dependent spliceosome that is particularly required for the splicing of the AT\u2013AC subtype. The Arabidopsis genome contains a single homolog, TITAN LIKE (TTL), but its function in splicing remains unknown. Here, we generated TTL mutants and isolated two viable alleles, of which we analyzed one, designated ttl-142, to investigate TTL function in splicing. ttl-142 carries a 42-nucleotide deletion that removes 14 amino acid residues from the predicted protein, and homozygous mutants exhibit morphological abnormalities. Most U12-dependent introns were less efficiently spliced in ttl-142 than in the wild-type, with the splicing of AT\u2013AC introns particularly suppressed. Splicing suppression in ttl-142 was more extensive than that in a DROL1 mutant, which carries a mutation in a gene specifically required for AT\u2013AC intron splicing. Conversely, fewer genes showed altered expression levels in ttl-142 than in drol1, and most differentially expressed genes differed between the two mutants. These results suggest that the phenotypes of ttl-142 and drol1 mutants may reflect the impairment of distinct spliceosomal functions.<\/p>","protected":false},"excerpt":{"rendered":"Tomoko Niwa, Junshin Miyamoto, Nao Iwase, Haruka Iwai, Takaaki Kojima, Takamasa Suzuki Abstract Many eukaryote […]","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-3539","post","type-post","status-publish","format-standard","hentry","category-article"],"_links":{"self":[{"href":"https:\/\/biochemistry.isc.chubu.ac.jp\/labo\/suzuki\/wp-json\/wp\/v2\/posts\/3539","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/biochemistry.isc.chubu.ac.jp\/labo\/suzuki\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/biochemistry.isc.chubu.ac.jp\/labo\/suzuki\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/biochemistry.isc.chubu.ac.jp\/labo\/suzuki\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/biochemistry.isc.chubu.ac.jp\/labo\/suzuki\/wp-json\/wp\/v2\/comments?post=3539"}],"version-history":[{"count":0,"href":"https:\/\/biochemistry.isc.chubu.ac.jp\/labo\/suzuki\/wp-json\/wp\/v2\/posts\/3539\/revisions"}],"wp:attachment":[{"href":"https:\/\/biochemistry.isc.chubu.ac.jp\/labo\/suzuki\/wp-json\/wp\/v2\/media?parent=3539"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/biochemistry.isc.chubu.ac.jp\/labo\/suzuki\/wp-json\/wp\/v2\/categories?post=3539"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/biochemistry.isc.chubu.ac.jp\/labo\/suzuki\/wp-json\/wp\/v2\/tags?post=3539"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}