Heterozygous mutation SLFN14 K208N in mice mediates species-specific differences in platelet and erythroid lineage commitment

Abstract

Schlafen 14 (SLFN14) has recently been identified as an endoribonuclease responsible for cleaving RNA to regulate and inhibit protein synthesis. Early studies revealed that members of the SLFN family are capable of altering lineage commitment during T-cell differentiation by using cell-cycle arrest as a means of translational control by RNase activity. SLFN14 has been reported as a novel gene causing an inherited macrothrombocytopenia and bleeding in human patients; however, the role of this endoribonuclease in megakaryopoiesis and thrombopoiesis remains unknown. To investigate this, we report a CRISPR knock-in mouse model of SLFN14 K208N homologous to the K219N mutation observed in our previous patient studies. We used hematological analysis, in vitro and in vivo studies of platelet and erythrocyte function, and analysis of spleen and bone marrow progenitors. Mice homozygous for this mutation do not survive to weaning age, whereas heterozygotes exhibit microcytic erythrocytosis, hemolytic anemia, splenomegaly, and abnormal thrombus formation, as revealed by intravital microscopy, although platelet function and morphology remain unchanged. We also show that there are differences in erythroid progenitors in the spleens and bone marrow of these mice, indicative of an upregulation of erythropoiesis. This SLFN14 mutation presents distinct species-specific phenotypes, with a platelet defect reported in humans and a severe microcytic erythrocytosis in mice. Thus, we conclude that SLFN14 is a key regulator in mammalian hematopoiesis and a species-specific mediator of platelet and erythroid lineage commitment.

Schlafens Can Put Viruses to Sleep

“…In addition, platelet function is diminished in patients with these mutations [61]. This SLFN14 mutation presents a species-specific phenotype, with platelet abnormalities in humans and severe microcytic erythrocytosis in mice [62]. Thus, SLFN14 may be an essential player in mammalian hematopoiesis, and may play a role in determining platelet and erythroid lineage commitment in particular species.…”

Schlafen14 Impairs HIV-1 Expression in a Codon Usage-Dependent Manner

“…Another member of the SLFN family, SLFN14, was discovered as a stalled ribosome-associated endoribonuclease, and the purified protein was shown to degrade ribosomes, tRNAs, and mRNA in vitro [ 41 , 42 , 43 ]. Furthermore, SLFN14 was found to degrade LINE-1 mRNA [ 44 ] in cells.…”