14–3‐3γ prevents centrosome duplication by inhibiting NPM1 function

Abstract

Partitioning of DNA into two daughter cells relies on the accurate organization of microtubules into a spindle (Reber & Hyman, 2015). Spindle organization in most mammalian cells is primarily dependent on the centrosome, which consists of two centrioles, a mother centriole and a daughter centriole, surrounded by the pericentriolar matrix (PCM) (Bornens, 2002;Brinkley et al., 1981;Mahen & Venkitaraman, 2012). The centrosome duplicates only once during a cell cycle (Hinchcliffe & Sluder, 2001) generating two centrosomes that nucleate a bipolar mitotic

Structural insights on the effects of mutation of a charged binding pocket residue on phosphopeptide binding to 14‐3‐3ζ protein

“…This observation comes exclusively from the MD simulations. (b) As predicted from our previous experimental studies on the γ isoform 19,27 and reiterated by investigations here on the ζ isoforms, D124A mutation induces local conformational changes and opens up the minor and major grooves that likely guard the entry and exit of the ligand; such a precise mapping is made possible by the comparative simulations of the WT and mutant proteins. (c) complementing these studies, the LIP-MS identifies a segment spanning 158-186 residues that is far more accessible/dynamic in the apo D124A mutant.…”

“…Mutation of Asp129 in 14-3-3γ to Alanine (D129A) leads to enhanced interaction with full length NPM1 which disrupts normal centrosome duplication. 19 These results indicate that D124 may play a context specific role in protein and peptide binding. At least peptide bound conformations and effect of any mutations on such short ligand binding are amenable to extensive MD simulations to dissect the underlying differences between wild type (WT) and mutant protein.…”

“…Recently it was shown 27 that mutation of Asp124–Ala (D124A) induces a conformational change in the protein structure, resulting in a significant reduction in peptide binding. Mutation of Asp129 in 14‐3‐3γ to Alanine (D129A) leads to enhanced interaction with full length NPM1 which disrupts normal centrosome duplication 19 . These results indicate that D124 may play a context specific role in protein and peptide binding.…”

“…Due to the multivariate roles they have in our cell, 14‐3‐3 proteins are widely studied using experimental 15 as well as computational (especially molecular dynamics [MD] simulations 16–18 ) methods to gain understanding about their structure and function. The minor differences in sequence and structure of various isoforms may have a role to play in distinct functions even within the same pathway 19 …”

“…The minor differences in sequence and structure of various isoforms may have a role to play in distinct functions even within the same pathway. 19 The heterogeneity and a sheer number of interacting partners of 14-3-3 proteins led to the speculation that there must be a common determinant for binding. The hypothesis was confirmed upon the identification of phosphoserine/phosphothreonine containing motifs present in many of the interacting partners.…”