Functional analyses of human LUC7-like proteins involved in splicing regulation and myeloid neoplasms
Noah J. Daniels,
Courtney E. Hershberger,
Xiaorong Gu,
Caroline Schueger,
William M. DiPasquale,
Jonathan Brick,
Yogen Saunthararajah,
Jaroslaw P. Maciejewski,
Richard A. Padgett
Affiliations
Noah J. Daniels
Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
Courtney E. Hershberger
Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
Xiaorong Gu
Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA
Caroline Schueger
Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA
William M. DiPasquale
Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
Jonathan Brick
Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
Yogen Saunthararajah
Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA
Jaroslaw P. Maciejewski
Department of Translational Hematology and Oncology Research, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, USA
Richard A. Padgett
Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Corresponding author
Summary: Vertebrates have evolved three paralogs, termed LUC7L, LUC7L2, and LUC7L3, of the essential yeast U1 small nuclear RNA (snRNA)-associated splicing factor Luc7p. We investigated the mechanistic and regulatory functions of these putative splicing factors, of which one (LUC7L2) is mutated or deleted in myeloid neoplasms. Protein interaction data show that all three proteins bind similar core but distinct regulatory splicing factors, probably mediated through their divergent arginine-serine-rich domains, which are not present in Luc7p. Knockdown of each factor reveals mostly unique sets of significantly dysregulated alternative splicing events dependent on their binding locations, which are largely non-overlapping. Notably, knockdown of LUC7L2 alone significantly upregulates the expression of multiple spliceosomal factors and downregulates glycolysis genes, possibly contributing to disease pathogenesis. RNA binding studies reveal that LUC7L2 and LUC7L3 crosslink to weak 5′ splice sites and to the 5′ end of U1 snRNA, establishing an evolutionarily conserved role in 5′ splice site selection.
