Natl Acad

Natl Acad. may play tasks in modulating the function of Ntc90p. Intro Introns are excised from precursor mRNA via a two-step reaction which happens in a large ribonucleoprotein complex called the spliceosome. The spliceosome is composed of five small nuclear RNAs (snRNAs), U1, U2, U4/U6 and U5, and a number of protein factors (for evaluations observe 1C6). Spliceosome assembly is definitely a stepwise process including sequential binding of snRNAs to the pre-mRNA in the order U1, U2, then U4/U6 and U5 like a pre-formed tri-snRNP particle. A subsequent conformational rearrangement, which results in dissociation of U1 and U4 accompanied by fresh foundation pair formation between U2 and U6, and between U6 and the 5 splice site, activates the spliceosome and allows the catalytic reactions to take place (7C13). It is believed that such structural rearrangements of the spliceosome are mediated by protein factors. Indeed, several splicing factors comprising the DEx(D/H) package motif have been shown to have RNA unwindase activity (6,14C16), although no substrate specificity has been demonstrated. Genetic analysis has provided evidence that Prp28p is definitely involved in unwinding the U1C5 splice site sequence and Brr2p may be responsible for unwinding of the U4/U6 duplex Digoxigenin prior to activation of the spliceosome (17C19). We have previously demonstrated that candida Prp19p protein is essential for pre-mRNA splicing and is associated with the spliceosome immediately after or concurrently with dissociation of U4 (20,21). Therefore, Prp19p is likely to play a role in mediating this structural switch in the spliceosome. Prp19p is not tightly associated with any of the spliceosomal snRNAs, but is associated with a protein complex consisting of at least eight protein parts (22). The association of Prp19p with this protein complex appears to be essential for its function. By a combination of genetic and biochemical methods we have previously recognized four components of the Prp19p-connected complex, Ntc85p, Ntc30p, Ntc25p (Snt309p) and Ntc20p (Ntc stands for PRP nineteen complex) (23C27). Ntc85p is essential for pre-mRNA splicing both and The DNA fragment retrieved from your candida genome by PCR with oligonucleotides 77-1 and 77-2 was digested with The DNA fragment retrieved from your candida genome by PCR with oligonucleotides 90-1 and 90-2 Digoxigenin was digested with The HA sequence was inserted into the C-terminus of Ntc77p in pLW7 by site-directed mutagenesis using oligonucleotide 77-3. The HA sequence was inserted into the C-terminus of Ntc90p in pLW9 by site-directed mutagenesis using oligonucleotide 90-3. The DNA Rabbit Polyclonal to OR4A15 fragment retrieved from your candida genome by PCR with oligonucleotides 31-1 and 31-2 was digested with The HA sequence was inserted into the C-terminus of Ntc31p in Digoxigenin pCHC3 by site-directed mutagenesis using oligonucleotide 31-3. A 3.4 kb gene was inserted into the A 3.4 kb A 2.7 kb gene was ligated having a 2.7 kb gene was ligated having a 2.7 kb gene was Digoxigenin ligated having a 1.4 kb gene was ligated having a 1.4 kb gene was ligated with and genes, and the complete gene, were isolated by PCR using oligonucleotides 77-1 and 77-2 for and 31-1 and 31-2 for and cloned into plasmid vector pRS406. The fragment contained Digoxigenin 270 bp of the ORF and its downstream sequence and the fragment contained 470 bp of the ORF and its downstream sequence. The HA epitope was then inserted into the C-terminus of each protein by site-directed mutagenesis using oligonucleotides 77-3, 90-3 and 31-3, respectively. The producing plasmids were linearized by digestion with a restriction enzyme within the ORFs and used to transform candida strain BJ2168 for directed integration. Correct integration was confirmed by Southern blotting. Production and purification of antibodies Ntc90p and Ntc31p were indicated in under control of the T7 promoter. Total lysates prepared from induced cells were fractionated by SDSCPAGE and the Ntc90p and Ntc31p proteins were eluted from gels for immunization of rabbits. Ntc77p was indicated like a GST fusion using plasmid vector pGEX-5x-3 (Gibco BRL) and the protein was purified by chromatography on a glutathione column for immunization of rabbits. To purify the antibodies, the recombinant proteins were conjugated to CNBr-activated Sepharose.