Structure of a Cell Polarity Regulator, a Complex between Atypical PKC and Par6 PB1 Domains

Hirano, Yoshinori; Yoshinaga, Sosuke; Takeya, Ryu; Suzuki, Nobuo; Horiuchi, Masataka; Kohjima, Motoyuki; Sumimoto, Hideki; Inagaki, Fuyuhiko

doi:10.1074/jbc.m409823200

Cited by 78 publications

(101 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Together, the electrostatic and hydrogen bond interactions at three paired sites of A1-B1, A2-B2 and A3-B3 within their PB1 domains lead to the formation of stable p62-PKCζ complex. Structural inspections of the reported PB1 homoand hetero-dimers demonstrated that some cognate pairs display auxiliary interactions in addition to the conserved A1-B1 and A2-B2 sites [24,32]. Based on sequence analysis ( Figure 1B), we believe that this additional A3-B3 interface plays a crucial role in the specific recognition between p62 and aPKCs.…”

Section: The Electrostatic Interactions Play a Dominant Role In P62-pmentioning

confidence: 91%

“…In human genome, there are at least 13 PB1-containing proteins that can form specific homo-or hetero-complexes to precisely modulate cellular signaling pathways, and a number of crystal/NMR structures of the homotypic PB1-PB1 complexes have been reported [24,32,34]. When these PB1 complexes were superimposed to our p62-PKCζ complex, the relative orientations between two interacting PB1 domains in different complexes may change remarkably (Figure 5A).…”

Section: The Apkc-pb1 Domains Belong To Type I Rather Than Type I/iimentioning

confidence: 98%

“…The structure was solved by molecular replacement using Phaser [23] with the structure of PKCι-Par6α PB1 complex (PDB ID: 1WMH) [24] as the search model. Standard refinement was performed with PHENIX [25] and Coot [26], and PROCHECK [27] was used to check the structure stereochemistry.…”

Section: Crystallization Data Collection and Structure Determinationmentioning

confidence: 99%

“…The type I group contains a conserved acidic motif (named the OPCA motif), while the type II group contains several lysine and/or arginine residues that form a basic surface opposite to the OPCA motif [10,30]. Therefore, the type I and type II PB1 domains can form heterodimers via electrostatic interactions [24,31,32]. The type I/II group contains both the OPCA motif and the basic surface, which enable the formation of homo-oligomers [8,33].…”

Section: Both Pb1 Domains Are Indispensable For the Interaction Betwementioning

confidence: 99%

“…The crystal belongs to space group P2 1 2 1 2 1 , and each asymmetric unit contains 12 identical p62-PKCζ heterodimers. Both PKCζ-PB1 and p62-PB1 in the complex structure display essentially the same topology as other PB1 domains, a ubiquitin-like β-grasp fold composed of one five-stranded β-sheet (β1-β5) and two α-helices [24,29,30,32,33,35,36]. The basic surface is mainly formed by the β1-β2 hairpin at the 'front' of the PB1 domain, whereas the acidic OPCA motif folds into the β3-β4 hairpin and helix α2 at the 'back' opposite to the basic side.…”

Section: Overall Structure Of a Heterodimeric Complex Between Pkcζ-pbmentioning

confidence: 99%

See 4 more Smart Citations

Structural and biochemical insights into the homotypic PB1-PB1 complex between PKCζ and p62

Ren

Wang

et al. 2013

Sci. China Life Sci.

View full text Add to dashboard Cite

The atypical PKC isoforms (ζ and ι) play essential roles in regulating various cellular processes. Both the hetero-interaction between PKCζ and p62 through their N-terminal PB1 domains and the homo-oligomerization of p62 via its PB1 domain are critical for the activation of NF-B signaling; however, the molecular mechanisms concerning the formation and regulation of these homotypic complexes remain unclear. Here we determined the crystal structure of PKCζ-PB1 in complex with a monomeric p62-PB1 mutant, where the massive electrostatic interactions between the acidic OPCA motif of PKCζ-PB1 and the basic surface of p62-PB1, as well as additional hydrogen bonds, ensure the formation of a stable and specific complex. The PKCζ-p62 interaction is interfered with the modification of a specific Cys of PKCζ by the antiarthritis drug aurothiomalate, though all four cysteine residues in the PKCζ-PB1 domain can be modified in in vitro assay. In addition, detailed structural and biochemical analyses demonstrate that the PB1 domains of aPKCs belong to the type I group, which can depolymerize the high-molecular-weight p62 aggregates into homo-oligomers of lower order. These data together unravel the molecular mechanisms of the homo-or hetero-interactions between p62 and PKCζ and provide the basis for designing inhibitors of NF-B signaling. The protein kinase C (PKC) family comprises a number of highly related serine/threonine kinases in mammals, which exert pivotal roles in many cellular processes and have been the focus of drug development in cancer, diabetic complications, heart failure and many other diseases [1][2][3]. Based on their cofactor requirements and sequence homology, these important kinases can be classified in three subfamilies: conventional (cPKC: α, β and γ), novel (nPKC: δ, ε, η and θ), and atypical (aPKC: ζ and ι/λ) [4]. The cPKCs are activated by both diacylglycerol (DAG) and Ca 2+ , and each cPKC consists of an N-terminal autoinhibitory pseudosubstrate motif, a DAG binding C1 domain and a Ca 2+ sensing C2 domain followed by the catalytic kinase domain. The nPKCs resemble the cPKCs but are only activated by DAG because their C2 domains do not bind Ca 2+ . The aPKC subfamily is unresponsive to both DAG and Ca 2+ due to the presence of an incomplete C1 domain and the lack of a C2 domain. Instead, the aPKCs are regulated by the PB1 (Phox and Bem1p) domain at their N-termini ( Figure 1A), which is one of the protein-interacting modules that undergo homotypic domain-domain interactions and thus mediate a number of cellular signaling pathways [5][6][7][8]. PKCζThe aPKC isoforms have been implicated in the regulation of many important signaling pathways such as NF-B signaling, cell polarity pathway and MAPK/ERK cascade, where the PB1-mediated interactions between aPKCs and

show abstract

Section: The Electrostatic Interactions Play a Dominant Role In P62-pmentioning

confidence: 91%

Section: The Apkc-pb1 Domains Belong To Type I Rather Than Type I/iimentioning

confidence: 98%

Section: Crystallization Data Collection and Structure Determinationmentioning

confidence: 99%

Section: Both Pb1 Domains Are Indispensable For the Interaction Betwementioning

confidence: 99%

Section: Overall Structure Of a Heterodimeric Complex Between Pkcζ-pbmentioning

confidence: 99%

See 3 more Smart Citations

Structural and biochemical insights into the homotypic PB1-PB1 complex between PKCζ and p62

Ren

Wang

et al. 2013

Sci. China Life Sci.

View full text Add to dashboard Cite

show abstract

Characterization of a novel TFG variant causing autosomal recessive pure hereditary spastic paraplegia

Hsiao,

Tsai,

Shen

et al. 2024

Ann Clin Transl Neurol

View full text Add to dashboard Cite

ObjectiveTFG mutations have previously been implicated in autosomal recessive hereditary spastic paraplegia (HSP), also known as SPG57. This study aimed to investigate the clinical and molecular features of TFG mutations in a Taiwanese HSP cohort.MethodsGenetic analysis of TFG was conducted in 242 unrelated Taiwanese HSP patients using a targeted resequencing panel covering the entire coding regions of TFG. Functional assays were performed using an in vitro cell model to assess the impact of TFG variants on protein function. Additionally, other representative TFG mutant proteins were examined to understand the broader implications of TFG mutations in HSP.ResultsThe study identified a novel homozygous TFG c.177A>C (p.(Lys59Asn)) variant in a family with adolescent‐onset, pure form HSP. Functional analysis revealed that the Lys59Asn TFG variant, similar to other HSP‐associated TFG mutants, exhibited a low affinity between TFG monomers and abnormal assembly of TFG homo‐oligomers. These structural alterations led to aberrant intracellular distribution, compromising TFG's protein secretion function and resulting in decreased cellular viability.InterpretationThese findings confirm that the homozygous TFG c.177A>C (p.(Lys59Asn)) variant is a novel cause of SPG57. The study expands our understanding of the clinical and mutational spectrum of TFG‐associated diseases, highlighting the functional defects associated with this specific TFG variant. Overall, this research contributes to the broader comprehension of the genetic and molecular mechanisms underlying HSP.

show abstract

Applications and Limitations of In Silico Models in Drug Discovery

Saçan

Ekins

Kortagere

2012

Methods in Molecular Biology

View full text Add to dashboard Cite

Drug discovery in the late twentieth and early twenty-first century has witnessed a myriad of changes that were adopted to predict whether a compound is likely to be successful, or conversely enable identification of molecules with liabilities as early as possible. These changes include integration of in silico strategies for lead design and optimization that perform complementary roles to that of the traditional in vitro and in vivo approaches. The in silico models are facilitated by the availability of large datasets associated with high-throughput screening, bioinformatics algorithms to mine and annotate the data from a target perspective, and chemoinformatics methods to integrate chemistry methods into lead design process. This chapter highlights the applications of some of these methods and their limitations. We hope this serves as an introduction to in silico drug discovery.

show abstract

Structure of a Cell Polarity Regulator, a Complex between Atypical PKC and Par6 PB1 Domains

Cited by 78 publications

References 45 publications

Structural and biochemical insights into the homotypic PB1-PB1 complex between PKCζ and p62

Structural and biochemical insights into the homotypic PB1-PB1 complex between PKCζ and p62

Characterization of a novel TFG variant causing autosomal recessive pure hereditary spastic paraplegia

Applications and Limitations of In Silico Models in Drug Discovery

Contact Info

Product

Resources

About