High impact information on FIP1

• Coimmunoprecipitation experiments reveal that RNA14, a subunit of cleavage factor I (CF I), directly interacts with FIP1, but not with PAP1 [1].
• Recombinant FIP1 protein forms a 1:1 complex with PAP1 in vitro [1].
• At 37 degrees C, a thermosensitive allele of FIP1 shows a shortening of poly(A) tails and a decrease in the steady-state level of actin transcripts [1].
• The FIP1 gene encodes a component of a yeast pre-mRNA polyadenylation factor that directly interacts with poly(A) polymerase [1].
• In contrast, the mutation of factors involved in the subsequent polyadenylation step (PAP1, FIP1, and YTH1) had little effect [2].

Biological context of FIP1

• We have identified an essential gene, called FIP1, encoding a 327 amino acid protein interacting with yeast poly(A) polymerase (PAP1) in the two-hybrid assay [1].
• We have sequenced a 61.989 bp stretch located between genes RAD7 and FIP1 of Saccharomyces cerevisiae chromosome X. This stretch contains 36 open reading frames (ORFs) of at least 100 codons [3].
• In vitro, Fip1 blocks access of the RNA primer to an RNA binding site (RBS) that overlaps the Fip1 carboxy-terminal interaction region and, in doing so, shifts PAP to a distributive mode of action [4].
• These data may help to elucidate the role of Fip1 in the mRNA 3'-OH polyadenylation process and the involvement of CK2 mediated phosphorylation in regulation of interactions and activity members of cleavage/polyadenylation factor (CPF) complex [5].
• According to the amino acid sequence Fip1 harbours twenty putative CK2 phosphorylation sites [5].

Associations of FIP1 with chemical compounds

• Fip1 regulates the activity of Poly(A) polymerase through multiple interactions [6].
• The C-terminal 789 amino acids of the Arabidopsis Fip1 protein were found to contain an RNA-binding domain; this domain correlated with an intact arginine-rich region and had a marked preference for poly(G) among the four homopolymers studied [7].

Physical interactions of FIP1

• We demonstrate that Yth1p is a component of PF I that interacts in vivo and in vitro with Fip1p, a known PF I subunit [8].

Other interactions of FIP1

• Yth1 was previously shown to interact with pre-mRNA and with two CPF subunits, Brr5/Ysh1 and the polyadenylation-specific Fip1, and to act in both steps of mRNA 3' end processing [9].

References