PMC:6288205 / 2893-4481 JSONTXT

{"project":"2_test","denotations":[{"id":"30471718-9725897-2047705","span":{"begin":204,"end":205},"obj":"9725897"},{"id":"30471718-15937072-2047706","span":{"begin":386,"end":387},"obj":"15937072"},{"id":"30471718-15750039-2047707","span":{"begin":1101,"end":1102},"obj":"15750039"},{"id":"30471718-26909801-2047708","span":{"begin":1104,"end":1105},"obj":"26909801"}],"text":"The outer dynein arms (ODAs) are responsible for the ciliary beat generation. ODAs and IDAs are large multimeric protein complexes that are pre-assembled in the cytoplasm before transport to the axonemes.3 In the unicellular alga Chlamydomonas reinhardtii, there is only one type of ODA which contains three dynein heavy chains: the α-dynein heavy chain (DHC), the β-DHC, and the γ-DHC.4 In contrast, in mammalian respiratory cilia, there are at least two types of ODAs, the ODA type 1 containing DNAH5 (ortholog of the γ-DHC) as well as DNAH11 (ortholog of the β-DHC) and the ODA type 2 containing DNAH5 and DNAH9 (also ortholog of the β-DHC). Using immunofluorescence analysis of human respiratory epithelial cells, we demonstrated in the past that the ODA heavy chains (HCs) show specific localization along the respiratory ciliary axonemes. The γ-HC DNAH5 shows a panaxonemal distribution along the ciliary axonemes. In contrast, the localization of the β-HC DNAH9 is restricted to the distal axonemal compartment while the paralogous β-HC DNAH11 is localized in the proximal axonemal compartment.5, 6 Thus, the human respiratory ciliary axoneme can be divided in two compartments, a proximal compartment defined by the ODA type 1 (containing DNAH11) and a distal compartment defined by the ODA type 2 (containing DNAH9). The identification of genes that encode for proteins responsible for correct composition and assembly of these distal and proximal protein complexes is critical to understand the disease mechanisms of motile ciliopathies such as primary ciliary dyskinesia (PCD)."}