• Something wrong with this record ?

Structural analysis of phosphatidylinositol 4-kinase IIIβ (PI4KB) - 14-3-3 protein complex reveals internal flexibility and explains 14-3-3 mediated protection from degradation in vitro

D. Chalupska, A. Eisenreichova, B. Różycki, L. Rezabkova, J. Humpolickova, M. Klima, E. Boura,

. 2017 ; 200 (1) : 36-44. [pub] 20170831

Language English Country United States

Document type Journal Article

Phosphatidylinositol 4-kinase IIIβ (PI4KB) is responsible for the synthesis of the Golgi and trans-Golgi network (TGN) pool of phosphatidylinositol 4-phospahte (PI4P). PI4P is the defining lipid hallmark of Golgi and TGN and also serves as a signaling lipid and as a precursor for higher phosphoinositides. In addition, PI4KB is hijacked by many single stranded plus RNA (+RNA) viruses to generate PI4P-rich membranes that serve as viral replication organelles. Given the importance of this enzyme in cells, it has to be regulated. 14-3-3 proteins bind PI4KB upon its phosphorylation by protein kinase D, however, the structural basis of PI4KB recognition by 14-3-3 proteins is unknown. Here, we characterized the PI4KB:14-3-3 protein complex biophysically and structurally. We discovered that the PI4KB:14-3-3 protein complex is tight and is formed with 2:2 stoichiometry. Surprisingly, the enzymatic activity of PI4KB is not directly modulated by 14-3-3 proteins. However, 14-3-3 proteins protect PI4KB from proteolytic degradation in vitro. Our structural analysis revealed that the PI4KB:14-3-3 protein complex is flexible but mostly within the disordered regions connecting the 14-3-3 binding site of the PI4KB with the rest of the PI4KB enzyme. It also predicted no direct modulation of PI4KB enzymatic activity by 14-3-3 proteins and that 14-3-3 binding will not interfere with PI4KB recruitment to the membrane by the ACBD3 protein. In addition, the structural analysis explains the observed protection from degradation; it revealed that several disordered regions of PI4KB become protected from proteolytical degradation upon 14-3-3 binding. All the structural predictions were subsequently biochemically validated.

References provided by Crossref.org

000      
00000naa a2200000 a 4500
001      
bmc18024689
003      
CZ-PrNML
005      
20180717092846.0
007      
ta
008      
180709s2017 xxu f 000 0|eng||
009      
AR
024    7_
$a 10.1016/j.jsb.2017.08.006 $2 doi
035    __
$a (PubMed)28864297
040    __
$a ABA008 $b cze $d ABA008 $e AACR2
041    0_
$a eng
044    __
$a xxu
100    1_
$a Chalupska, Dominika $u Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague 6, Czech Republic.
245    10
$a Structural analysis of phosphatidylinositol 4-kinase IIIβ (PI4KB) - 14-3-3 protein complex reveals internal flexibility and explains 14-3-3 mediated protection from degradation in vitro / $c D. Chalupska, A. Eisenreichova, B. Różycki, L. Rezabkova, J. Humpolickova, M. Klima, E. Boura,
520    9_
$a Phosphatidylinositol 4-kinase IIIβ (PI4KB) is responsible for the synthesis of the Golgi and trans-Golgi network (TGN) pool of phosphatidylinositol 4-phospahte (PI4P). PI4P is the defining lipid hallmark of Golgi and TGN and also serves as a signaling lipid and as a precursor for higher phosphoinositides. In addition, PI4KB is hijacked by many single stranded plus RNA (+RNA) viruses to generate PI4P-rich membranes that serve as viral replication organelles. Given the importance of this enzyme in cells, it has to be regulated. 14-3-3 proteins bind PI4KB upon its phosphorylation by protein kinase D, however, the structural basis of PI4KB recognition by 14-3-3 proteins is unknown. Here, we characterized the PI4KB:14-3-3 protein complex biophysically and structurally. We discovered that the PI4KB:14-3-3 protein complex is tight and is formed with 2:2 stoichiometry. Surprisingly, the enzymatic activity of PI4KB is not directly modulated by 14-3-3 proteins. However, 14-3-3 proteins protect PI4KB from proteolytic degradation in vitro. Our structural analysis revealed that the PI4KB:14-3-3 protein complex is flexible but mostly within the disordered regions connecting the 14-3-3 binding site of the PI4KB with the rest of the PI4KB enzyme. It also predicted no direct modulation of PI4KB enzymatic activity by 14-3-3 proteins and that 14-3-3 binding will not interfere with PI4KB recruitment to the membrane by the ACBD3 protein. In addition, the structural analysis explains the observed protection from degradation; it revealed that several disordered regions of PI4KB become protected from proteolytical degradation upon 14-3-3 binding. All the structural predictions were subsequently biochemically validated.
650    _2
$a proteiny 14-3-3 $x chemie $7 D048948
650    _2
$a krystalografie rentgenová $7 D018360
650    _2
$a lidé $7 D006801
650    _2
$a vodíková vazba $7 D006860
650    _2
$a molekulární modely $7 D008958
650    _2
$a fosfotransferasy s alkoholovou skupinou jako akceptorem $x chemie $7 D017853
650    _2
$a vazba proteinů $7 D011485
650    _2
$a konformace proteinů, alfa-helix $7 D000072756
650    _2
$a interakční proteinové domény a motivy $7 D054730
650    _2
$a kvarterní struktura proteinů $7 D020836
650    _2
$a proteolýza $7 D059748
650    _2
$a maloúhlový rozptyl $7 D053838
655    _2
$a časopisecké články $7 D016428
700    1_
$a Eisenreichova, Andrea $u Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague 6, Czech Republic.
700    1_
$a Różycki, Bartosz $u Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw, Poland.
700    1_
$a Rezabkova, Lenka $u Laboratory of Biomolecular Research, Department of Biology and Chemistry, Paul Scherrer Institute, 5232, Villigen PSI, Switzerland.
700    1_
$a Humpolickova, Jana $u Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague 6, Czech Republic.
700    1_
$a Klima, Martin $u Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague 6, Czech Republic.
700    1_
$a Boura, Evzen $u Institute of Organic Chemistry and Biochemistry AS CR, v.v.i., Flemingovo nam. 2., 166 10 Prague 6, Czech Republic. Electronic address: boura@uochb.cas.cz.
773    0_
$w MED00002951 $t Journal of structural biology $x 1095-8657 $g Roč. 200, č. 1 (2017), s. 36-44
856    41
$u https://pubmed.ncbi.nlm.nih.gov/28864297 $y Pubmed
910    __
$a ABA008 $b sig $c sign $y a $z 0
990    __
$a 20180709 $b ABA008
991    __
$a 20180717093145 $b ABA008
999    __
$a ok $b bmc $g 1316820 $s 1021610
BAS    __
$a 3
BAS    __
$a PreBMC
BMC    __
$a 2017 $b 200 $c 1 $d 36-44 $e 20170831 $i 1095-8657 $m Journal of structural biology $n J Struct Biol $x MED00002951
LZP    __
$a Pubmed-20180709

Find record

Citation metrics

Loading data ...

Archiving options

Loading data ...