RNA sequencing reveals global gene expression changes in response to codanin-1 knockdown in erythroid-committed cells

Congenital dyserythropoietic anemia type I (CDA-I) is an autosomal recessive disorder marked by ineffective erythropoiesis, abnormal morphology of bone marrow erythroblasts, and iron overload. Most cases of CDA-I are caused by mutations in the CDAN1 gene, which encodes for a ubiquitous protein of unknown function, codanin-1. To study the function of codanin-1 in CDA-I erythroid pathophysiology several erythroid models were developed. Here we show that codanin-1 expression is required for erythroid progenitor development and normal erythroid cell differentiation. Erythroid cells lacking codanin-1 demonstrated morphologic changes similar to that observed in CDA-I. Global gene expression changes after codanin-1 knockdown revealed alterations in a set of key erythroid genes. In particular, the AHSP gene, which showed decreased mRNA expression after codanin-1 knockdown in CD34+ cells, also demonstrated increased codanin-1 occupancy at its gene regulatory region by chromatin immunoprecipitation coupled to high-throughput sequencing. Using cell models recapitulating many features of CDA-I, we have confirmed the importance of codanin-1 during erythroid differentiation and provide mechanistic insight into how loss of codanin-1 expression results in CDA-I. Overall design: RNA-Seq was used to analyze the effects of CDAN1 (codanin-1) knockdown in erythroid-induced human primary cells transduced with non-targeting shRNA (shControl) or shRNAs targeting different regions of CDAN1, the 3'UTR or the coding sequence.