Differential expression of CARMIL‐family genes during zebrafish development

Abstract

CARMILs are a conserved family of large multidomain proteins that regulate and target actin assembly by interacting with actin capping protein (CP). Vertebrates contain three highly conserved CARMIL isoforms encoded by three genes, whereas lower organisms contain only one isoform and gene. In order to investigate the functions of vertebrate CARMILs, we identified and characterized the three CARMIL genes in zebrafish (Danio rerio). We isolated and sequenced complete and partial cDNAs from embryos. The three genes display distinct spatial and temporal expression patterns during development. Sequence and phylogenetic analyses of cDNAs and predicted protein sequences reveal that the three zebrafish genes fall into the three conserved isoform groups previously defined for other vertebrates, which have isoform-specific and overlapping functions in human cultured cells. These results provide new tools and offer insight into understanding the role of the regulation of actin assembly dynamics during embryonic development and tissue morphogenesis.

CARMIL3 is important for cell migration and morphogenesis during early development in zebrafish

“…However, our study does not include an analysis of the protein products that would test this view definitively. The observation that only maternal zygotic but not zygotic carmil3 mutants presented gastrulation phenotypes, is consistent with known significant maternal carmil3 expression, which is likely to compensate for the lack of zygotic expression during gastrulation (Solnica-Krezel, 2020; Stark and Cooper, 2015). The lack of full penetrance for the later phenotypes indicates a substantial level of robustness in the processes of cell migration and morphogenesis, consistent with observations for many other genes regulating early embryogenesis (Chen et al, 2018;Kelly et al, 2000;Li-Villarreal et al, 2015;Solnica-Krezel and Driever, 2001).…”

“…CARMILs are one family of capping-protein-interacting (CPI-motif) proteins, reviewed in (Edwards et al, 2014). Vertebrates, including zebrafish, have three conserved CARMILencoding genes, called CARMIL1, CARMIL2 and CARMIL3 in humans (Stark et al, 2017;Stark and Cooper, 2015). The zebrafish genes, carmil1, carmil2 and carmil3, have distinct spatial and temporal expression patterns during development (Stark and Cooper, 2015).…”

“…Vertebrates, including zebrafish, have three conserved CARMILencoding genes, called CARMIL1, CARMIL2 and CARMIL3 in humans (Stark et al, 2017;Stark and Cooper, 2015). The zebrafish genes, carmil1, carmil2 and carmil3, have distinct spatial and temporal expression patterns during development (Stark and Cooper, 2015). In human cultured cells, available evidence indicates that the gene products have distinct subcellular locations and functions, even within one cell type (Lanier et al, 2015;Liang et al, 2009;Stark et al, 2017).…”

CARMIL family proteins as multidomain regulators of actin-based motility

“…Of the three, CARMIL1 is most widely expressed, being present in the skin, fins, branchial arches, gut, and cloaca (Stark and Cooper, 2015). An RNA-sequencing study of zebrafish skin found only the CARMIL1 isoform ( Wang, Cokus, and Sagasti, personal communication).…”

“…Amoebozoa and invertebrates have one gene encoding CARMIL, whereas vertebrates have three ( Liang et al , 2009 ; Edwards et al , 2014 ; Stark and Cooper, 2015 ), and the genomes of fungi and plants appear to lack CARMIL homologues altogether. The three vertebrate isoforms, CARMIL1, 2, and 3, can be defined and distinguished from each other by conserved differences in their amino acid sequences ( Figure 1 ).…”