General and specific promotion of flagellar assembly by a flagellar nucleoside diphosphate kinase

Abstract

NDK5 promotes assembly of motile cilia and flagella with its structure and protein phosphorylation–related reactions instead of the canonical NDK activity. The novel mechanisms and dominant-negative effect of mutated functional NDK5 reveal the remarkable versatility of a molecular platform that is used in diverse cellular processes.

The roles of a flagellar HSP40 ensuring rhythmic beating

“…Comparisons of RS deficiencies among mutants suggest that RSP2, NDK5, and HSP40 are located at the spoke neck of mature RSs (Table 1) (Huang et al ., 1981; Patel-King et al ., 2004; Yang et al ., 2005; Pigino et al ., 2011). While RSP2 is crucial for the assembly of all head and neck proteins, only NDK5 is directly required for the assembly of HSP40 (Zhu et al ., 2017b). To test whether HSP40 and NDK5 interact directly, we performed a pull-down assay, which was used to identify interacting RSPs (Kohno et al.…”

“…We first characterized individual polypeptides suitable for in vitro studies. While full-length recombinant NDK5 precipitated, the conserved N-terminal 201 amino acids (a.a.), including the NDK domain and the Dpy30 domain, were soluble and exhibited NDK activity (Zhu et al. , 2017b).…”

“…Yet mature and precursor RSs appear rather different in several ways. In contrast to 20S Y-shaped mature RSs, RS precursors sediment as 12S Γ-shaped particles (Yang et al ., 2001; Qin et al ., 2004; Diener et al ., 2011), lacking HSP40 (Yang et al ., 2005) and the signature bifurcated neck, where HSP40 is predicted to reside (Pigino et al ., 2011; Zhu et al. , 2017b).…”

Structure, Folding and Stability of Nucleoside Diphosphate Kinases

“…NDPKs thus produce GTP for elongation in protein synthesis, signal transduction and microtubule polymerization; CTP for the synthesis of lipids; UTP for the synthesis of polysaccharides and NTPs or dNTPs for the synthesis of nucleic acids. In addition to these well-established metabolic functions [ 7 , 8 , 9 , 10 ], other important roles have been identified: some isoforms can bind DNA [ 11 , 12 ], act as metastasis suppressors [ 1 , 13 , 14 ], participate in membrane remodeling through interaction with dynamins [ 1 , 15 ] or influence cytoskeleton dynamics [ 16 , 17 ].…”

“…The involvement of NDPKs in different aspects of metastasis is particularly important. The interaction between NDPKs and cytoskeletal components such as actin, actin binding proteins, intermediate filaments and tubulin has been described by several groups and is thought to be highly relevant in the context of metastasis, partially due to the well-established role of cytoskeleton in cell motility and metastasis spread [ 16 , 17 ]. In addition, its ability to interact with other key players in cancer metastasis, such as small GTPases, G protein coupled receptors (GPCRs), ion channels, extra cellular matrix and vascular basal membrane proteins, suggests that NDPK is an important upstream regulator of multiple cancer metastasis signaling pathways [ 1 , 18 ].…”