Abstract
LSD1/KDM1A is a widely conserved lysine-specific demethylase that removes methyl groups from methylated proteins, mainly histone H3. We previously isolated the zebrafish LSD1 gene and demonstrated that it is required for primitive hematopoiesis. Recently, a neuron-specific splicing variant of LSD1 was found in mammals and its specific functions and substrate specificities were reported. To our surprise, zebrafish LSD1 cDNA, which we previously analyzed, was corresponded to the neuron-specific variant in mammals. In this study, we investigated the structures and expression of LSD1 splicing variants in zebrafish and found all 4 types of LSD1 isoforms: LSD1, LSD1+2al, LSD1+8al and LSD1+2al8al. Interestingly, LSD1+8al/LSD1+2al8al, which correspond to mammalian neuron-specific variants, expressed ubiquitously in zebrafish. We also performed phenotypic rescue experiments of a zebrafish LSD1 mutant (kdm1ait627) using human and zebrafish LSD1 variants to identify which variant is involved in primitive hematopoiesis. Unexpectedly, the overexpression of all types of human and zebrafish variants was able to rescue the hematopoietic phenotypes in LSD1 mutants. Furthermore, enzymatic-deficient LSD1K661A (human) and K638A (zebrafish) were also able to rescue the mutant phenotypes. These results suggest that the LSD1 functions in zebrafish primitive hematopoiesis are free from any splicing-dependent regulation or demethylation reaction.
Highlights
LSD1/KDM1A is a widely conserved lysine-specific demethylase that removes methyl groups from methylated proteins, mainly histone H3
LSD1, we first searched for them in the zebrafish genomic database at Ensembl Genome Server and found two full-length zebrafish LSD1 variants, both of which were different from the one we had cloned previously (Fig. 1A, ours). kdm1a-208 is a LSD1 isoform without extra peptides, while kdm1a-201 contains two extra peptides, GERCTS and ING, at the equivalent sites of the mammalian splicing variants LSD1+8a and LSD1+2a, respectively (Fig. 1B,C)
These findings suggest that both LSD1 splicing variants with and without 8a/8a- and 2a/2a-like peptides are widely conserved among vertebrates
Summary
LSD1/KDM1A is a widely conserved lysine-specific demethylase that removes methyl groups from methylated proteins, mainly histone H3. A neuron-specific splicing variant of LSD1, named LSD1+8a or neuroLSD1, which contains micro-exon 8a, was identified in humans and mice[8] and has recently been shown to have a different substrate preference from the ubiquitously expressed LSD1 isoform, which has no extra exons[9,10]. The insertion site of the GERCTS peptide in our zebrafish LSD1 matched exactly to LSD1+8a in humans and mice in spite of a differing peptide www.nature.com/scientificreports sequence (DTVK) (Fig. 1B) This prompted us to hypothesize that 1) the LSD1+8a type splicing variant in mammals is conserved in fish, and 2) this isoform plays roles in primitive hematopoiesis. We analyzed the alternative splicing profiles of zebrafish LSD1 in various conditions and carried out rescue experiments of hematopoietic defects in LSD1 mutant embryos using human LSD1 splicing variants in the present study
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
