Solution NMR assignment of the C-terminal domain of human chTOG

Elena Rostkova,Selena G Burgess,Richard Bayliss,Mark Pfuhl

doi:10.1007/s12104-018-9812-9

Elena Rostkova, Selena G Burgess + Show 2 more

Open Access

https://doi.org/10.1007/s12104-018-9812-9

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Abstract

The microtubule regulatory protein colonic and hepatic tumor overexpressed gene (chTOG), also known as cytoskeleleton associated protein 5 (CKAP5) plays an important role in organizing the cytoskeleton and in particular in the assembly of k-fibres in mitosis. Recently, we dissected the hitherto poorly understood C-terminus of this protein by discovering two new domains—a cryptic TOG domain (TOG6) and a smaller, helical domain at the very C-terminus. It was shown that the C-terminal domain is important for the interaction with the TACC domain in TACC3 during the assembly of k-fibres in a ternary complex that also includes clathrin. Here we now present the solution NMR assignment of the chTOG C-terminal domain which confirms our earlier prediction that it is mainly made of α-helices. However, the appearance of the 1H–15N HSQC spectrum is indicative of the presence of a considerable amount of unstructured and possibly flexible portions of protein in the domain.

Highlights

The human protein colonic and hepatic tumor overexpressed gene, known as cytoskeleleton associated protein 5 (CKAP5), and its Drosophila melanogaster homologue, MSPS are members of the XMAP215 protein family (Ohkura et al 2001)
XMAP215 proteins play an important role in the assembly of kinetochore fibres as they help to crosslink adjacent microtubules in a complex with clathrin and transforming acidic coiled-coil protein 3 (TACC3)
Of the complex is regulated by AuroraA phosphorylation of TACC3 as phosphorylation on Ser558 (TACC3 numbering) is required for the subsequent interaction between clathrin and TACC3 (Hood et al 2013)

Summary

Biological context

The human protein colonic and hepatic tumor overexpressed gene (chTOG), known as CKAP5, and its Drosophila melanogaster homologue, MSPS (mini spindles) are members of the XMAP215 protein family (Ohkura et al 2001) These proteins vary considerably in size and consist of an N-terminal region comprising 2, 3 or 5 highly conserved TOG domains followed by a C-terminal region that is much more diverse in sequence and varying in length. These results suggest that the binding site for the TACC domain resides in the CTD and not in the cryptic TOG6 domain This makes a study of the chTOG CTD an important step in dissecting k-fibre assembly

Methods and experiments

Findings

Assignments and data deposition