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Exploring the effect of conserved motifs on the structure and activity of the RNA‐binding protein LARP6c from Arabidopsis thaliana
Author(s) -
Foster Jessica Sara,
Foster Corina L.,
OttePetrill Courtney,
Betancourt Francisco C.,
Lewis Karen A.,
Antonelli Cecile,
Billey Elodie
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.790.7
Subject(s) - rna recognition motif , rna , rna binding protein , biology , structural motif , arabidopsis , sequence motif , microbiology and biotechnology , genetics , biochemistry , gene , mutant
La Related Protein 6 (LARP6) is an RNA binding protein that belongs to the La‐Related Protein superfamily (LARPS). LARP6 contains structural motifs that are conserved across vertebrates and invertebrates. In vertebrates, LARP6 regulates the translation of collagen mRNA and thereby the synthesis of type I collagen. However, the biological function of LARP6 in plants is not well understood. Plants express three LARP6 paralogs: LARP6a, LARP6b, and LARP6c. Our study focuses on Arabidopsis thaliana LARP6c ( At LARP6c), which contains three structural motifs: a poly‐A binding protein (PABP)‐interacting motif 2 (PAM2), an RNA‐binding domain consisting of the La module comprised of the La motif and RNA recognition motif (RRM), and a C‐terminal La‐and SUZ‐C associated (LSA) motif. We hypothesize that the PAM2 motif may affect the RNA binding activity of At LARP6c. To test this hypothesis, we recombinantly expressed and purified three forms of At LARP6c: full length At LARP6c, At LARP6c‐ΔPAM2, and the isolated La module. Limited proteolysis was used to probe the structural stability of the purified proteins, demonstrating that the three constructs were stably folded. Our current work is now focused on establishing electrophoretic mobility shift assays with biotinylated RNA ligands to test the role of the deleted protein domains on the RNA binding activity of our At LARP6c variants. Previous published studies found that full length At LARP6c binds to polyA, polyU, and polyC oligonucleotides. These same ligands are being used to directly test how the PAM2 and auxiliary domains of At LARP6c affect the RNA binding activity of the La module. This investigation provides insight into potential regulatory mechanisms of RNA binding in the plant LARP6 proteins. Support or Funding Information Support provided by Texas State University and the National Institutes of Health ‐ National Institute of General Medical Studies (GM119096) to K.A.L. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .