Solution structure and p43 binding of the p38 leucine zipper motif: coiled‐coil interactions mediate the association between p38 and p43

Abstract

p38, which has been suggested to be a sca¡old protein for the assembly of a macromolecular tRNA synthetase complex, contains a leucine zipper-like motif. To understand the importance of the leucine zipper-like motif of p38 (p38LZ) in macromolecular assembly, the p38LZ solution structure was investigated by circular dichroism and nuclear magnetic resonance spectroscopy. The solution structure of p38LZ showed an amphipathic K K-helical structure and characteristics similar to a coiled-coil motif. The protein^protein interaction mediated by p38LZ was examined by an in vitro binding assay. The p43 protein, another non-synthetase component of the complex, could bind to p38LZ via its N-terminal domain, which is also predicted to have a potential coiled-coil motif. Thus, we propose that the p38^p43 complex would be formed by coiledcoil interactions, and the formation of the binary complex would facilitate the macromolecular assembly of aminoacyl-tRNA synthetases. ß

Hierarchical Network between the Components of the Multi-tRNA Synthetase Complex

“…1A) and real-ime RT-PCR (supplemental Table 1 The Effect of Depletion of AIMPs-AIMP2 has been shown by in vivo analysis (26) to be critical for the integrity of the whole complex and the stability of its components. It interacts with AIMP1 via a coiled-coil interaction (27). We found that depletion of any one of the three AIMPs greatly affected the levels of the others (Fig.…”

Accumulation of the Authentic Parkin Substrate Aminoacyl-tRNA Synthetase Cofactor, p38/JTV-1, Leads to Catecholaminergic Cell Death

“…p38 contains two functional domains, such as leucine zipper domain at its N terminus, which is involved in macromolecular assembly of ARSs (Quevillon et al, 1999;Ahn et al, 2003) and a GST-homology domain at the C terminus. We did not observe an interaction with parkin in these functional domains; instead, mapping studies indicate that parkin mainly interacts with the 82-162 domain of p38.…”

The N Terminus of Pro-endothelial Monocyte-activating Polypeptide II (EMAP II) Regulates Its Binding with the C Terminus, Arginyl-tRNA Synthetase, and Neurofilament Light Protein

“…The N terminus contains a coiled-coil structure, which may play an important role in protein-protein interaction. Furthermore, the N terminus of pro-EMAP II has been reported to interact with its own N terminus, p38, RARS, QARS, and the leucine zipper of AIMP2 (21,23,24,38), suggesting that the N terminus may mediate the association of pro-EMAP II to MSC. However, the structure and function of N terminus of pro-EMAP II remains obscure.…”

“…Intracellularly, pro-EMAP II directly interacts with other components of the MSC, such as p38, arginyl-tRNA synthetase (RARS), and glutaminyl-tRNA synthetase (QARS) (21)(22)(23)(24). Such an interaction plays an important role in the assembly and function of the MSC.…”