Nalazite se na CroRIS probnoj okolini. Ovdje evidentirani podaci neće biti pohranjeni u Informacijskom sustavu znanosti RH. Ako je ovo greška, CroRIS produkcijskoj okolini moguće je pristupi putem poveznice www.croris.hr
izvor podataka: crosbi

Evidence for a complex regulation of Pho4 action in S. cerevisiae (CROSBI ID 467572)

Prilog sa skupa u zborniku | sažetak izlaganja sa skupa | domaća recenzija

Korica, Tamara ; Gregory, Philip D. ; Horz, Wolfram ; Barbarić, Slobodan Evidence for a complex regulation of Pho4 action in S. cerevisiae // Godišnji sastanak hrvatskih biokemičara, 1998 / Glavaš-Obrovac, Ljubica (ur.). Zagreb: Farmaceutsko-biokemijski fakultet Sveučilišta u Zagrebu, 1998. str. 93-93-x

Podaci o odgovornosti

Korica, Tamara ; Gregory, Philip D. ; Horz, Wolfram ; Barbarić, Slobodan

engleski

Evidence for a complex regulation of Pho4 action in S. cerevisiae

Transcriptional activation of the yeast PHO5 promoter upon phosphate starvation requires two transcriptional activators, the bHLH protein Pho4 and the homeodomain protein Pho2. The two proteins bind to the promoter in a cooperative manner. Cooperativity requires DNA binding of both proteins as well as specific Pho2-Pho4 interaction. The activity of Pho4 is regulated through phosphorylation by Pho80-Pho85, a cyclin-cdk complex. Under repressing conditions Pho4 is phosphorylated and located predominantly in the cytoplasm. However, although non-phosphorylatable Pho4 derivatives are constitutively localised in the nucleus, activity of PHO5 in a strain expressing such mutants still increases 4 times upon induction, showing that there is yet another mechanism regulating PHO5 expression which is independent of Pho80-Pho85. In addition to six Pho85 consensus target sites, Pho4 contains two putative PKA phosphorylation sites, one being located in the basic region (Ser 254), which is involved in interactions with Pho2. We have therefore examined the possible role of Ser254 phosphorylation in the regulation of Pho4-Pho2 interactions and consequently the ability of Pho4 to bind DNA and activate transcription. To this end, we introduced two mutations into Pho4 at this residue (S254A and S254D). Expression of PHO5 in a strain containing the Pho4 derivative (S254A) was 2-3 times higher at repressive conditions than with wt Pho4, but only slightly higher at induced conditions. On the other hand, the S254D mutation, which mimicks constitutively phosphorylated Ser254, was without a significant effect at repressive conditions, but results in more than 2-fold lower activation at induced conditions, indicating that phosphorylation of Ser254 is involved in the regulation of Pho4 activity. Experiments testing the ability of the mutant Pho4 proteins to interact with Pho2 and to bind DNA are in progress.

transcriptional regulation; PHO5; Pho4; Saccharomyces cerevisiae

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

nije evidentirano

Podaci o prilogu

93-93-x.

1998.

objavljeno

Podaci o matičnoj publikaciji

Godišnji sastanak hrvatskih biokemičara, 1998

Glavaš-Obrovac, Ljubica

Zagreb: Farmaceutsko-biokemijski fakultet Sveučilišta u Zagrebu

Podaci o skupu

Godišnji sastanak hrvatskih biokemičara

poster

17.09.1998-20.09.1998

Hrvatska

Povezanost rada

Prehrambena tehnologija