Identification of proteins that form specific complexes with the highly conserved protein Translin in Schizosaccharomyces pombe

Abstract

Translin is a single-stranded DNA and RNA binding protein that has a high affinity for G-rich sequences. TRAX is a Translin paralog that associates with Translin. Both Translin and TRAX were highly conserved in eukaryotes. The nucleic acid binding form of Translin is a barrel-shaped homo-octamer. A Translin-TRAX hetero-octamer having a similar structure also binds nucleic acids. Previous reports suggested that Translin may be involved in chromosomal translocations, telomere metabolism and the control of mRNA transport and translation. More recent studies have indicated that Translin-TRAX hetero-octamers are involved in RNA silencing. To gain a further insight into the functions of Translin, we have undertaken to systematically search for proteins with which it forms specific complexes in living cells. Here we report the results of such a search conducted in the fission yeast Schizosaccharomyces pombe, a suitable model system. This search was carried out by affinity purification and immuno-precipitation techniques, combined with differential labeling of the intracellular proteins with the stable isotopes ¹⁵N and ¹⁴N. We identified for the first time two proteins containing an RNA Recognition Motif (RRM), which are specifically associated with the yeast Translin: (1) the pre-mRNA-splicing factor srp1 that belongs to the highly conserved SR family of proteins and (2) vip1, a protein conserved in fungi. Our data also support the presence of RNA in these intracellular complexes. Our experimental approach should be generally applicable to studies of weak intracellular protein-protein interactions and provides a clear distinction between false positive vs. truly interacting proteins.

Translin and Trax differentially regulate telomere-associated transcript homeostasis

“…This suggests that telomere-associated transcriptome regulation by TSN and/or TSNAX in humans is likely mediated by an indirect and/or transient/labile association [51]. In S. pombe , Translin (Tsn1) only forms weak interactions with other non-Trax (Tfx1) proteins [52], and possibly other macromolecules, and no interactions have been demonstrated with known telomere regulators.…”

A Phytophthora capsici Effector Targets ACD11 Binding Partners that Regulate ROS-Mediated Defense Response in Arabidopsis

“…We noticed that BPA1 and BPLs share high sequence similarity with Schizosaccharomyces pombe VIP1 (Supplemental Figure 8A), which is an inositol pyrophosphate synthase that interacts with Translin and is involved in regulating cyclin/ cyclin-dependent kinase (Eliahoo et al, 2014). Therefore, we speculated that Arabidopsis Translin (Supplemental Figure 8B) might interact with BPA1 and BPLs.…”

Translin facilitates RNA polymerase II dissociation and suppresses genome instability during RNase H2- and Dicer-deficiency

“…Eliahoo and co-workers [ 82 ] identified the S . pombe pre-mRNA splicing factor Srp1 as a putative Tsn1 binding partner.…”

“…Eliahoo and co-workers [82] identified the S. pombe pre-mRNA splicing factor Srp1 as a putative Tsn1 binding partner. Efficient cleavage of pre-mRNAs is known to prevent genomic instability associated with DNA replication stress [83] and introns protect genomes from replicative stress, indicating that some feature of spliceosome-associated processing is protective [84].…”