Crystal Structure and Allosteric Activation of Protein Kinase C βII

Leonard, Thomas A.; Różycki, Bartosz; Saidi, Layla; Hummer, Gerhard; Hurley, James H.

doi:10.1016/j.cell.2010.12.013

Cited by 169 publications

(203 citation statements)

References 58 publications

Supporting

Mentioning

193

Contrasting

Unclassified

Order By: Relevance

“…S1A). Additionally, there was little difference in the degree of activation loop phosphorylation among the variants, with the exception that the K293W ATP binding pocket mutant (27) showed severely reduced modification (Supplemental Fig. S1B).…”

Section: Resultsmentioning

confidence: 99%

Partitioning-defective Protein 6 (Par-6) Activates Atypical Protein Kinase C (aPKC) by Pseudosubstrate Displacement

Graybill

Wee

Atwood

et al. 2012

Journal of Biological Chemistry

117

View full text Add to dashboard Cite

The phosphorylation activity of atypical Protein Kinase C (aPKC) is central to the establishment of cell polarity by Par complex. Like other PKC family members, aPKC contains a pseudosubstrate domain that binds to the active site in the kinase domain and acts as an internal inhibitor. Despite the presence of the cis‐acting inhibitor, another Par complex member, Par‐6, is thought to repress aPKC activity. To examine the precise mechanism by which the pseudosubstrate domain and Par‐6 regulate aPKC activity, we reconstitute the system in vitro and performed a detailed kinetic analysis. We confirm that the pseudosubstrate domain is responsible for the autoinhibition. Surprisingly, rather than acting as an inhibitor, Par‐6 activates aPKC by displacing the pseudosubstrate from the kinase domain. Par‐6 activation of aPKC is consistent with our observation that Par‐6/aPKC complex, but not aPKC alone, is competent to release its substrate from the cell membrane in Drosophila S2 cells. Our data support a model in which Par‐6 displacement of aPKC pseudosubstrate domain is required for the diverse cell polarities mediated by the Par complex. NIH Grant 068032

show abstract

Section: Resultsmentioning

confidence: 99%

Partitioning-defective Protein 6 (Par-6) Activates Atypical Protein Kinase C (aPKC) by Pseudosubstrate Displacement

Graybill

Wee

Atwood

et al. 2012

Journal of Biological Chemistry

117

View full text Add to dashboard Cite

show abstract

“…The FDDY motif in the C-terminal tail of some AGC kinases (e.g., Akt, PRK2, and PKA) is thought to serve as an important docking site for PDK1, which lacks its own FDDY motif (28); the recently explained structure of full-length PKCβII shows how the Phe residue of the FDDY motif also can serve as a docking site for its own C1B domain (29). There also is a critical phosphorylation site in the C-tail that, in the case of PKA, is added cotranslationally while the C-subunit is still on the ribosome.…”

Section: Resultsmentioning

confidence: 99%

Localization and quaternary structure of the PKA RIβ holoenzyme

Ilouz

Bubis

Wu³

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Specificity for signaling by cAMP-dependent protein kinase (PKA) is achieved by both targeting and isoform diversity. The inactive PKA holoenzyme has two catalytic (C) subunits and a regulatory (R) subunit dimer (R 2 :C 2 ). Although the RIα, RIIα, and RIIβ isoforms are well studied, little is known about RIβ. We show here that RIβ is enriched selectively in mitochondria and hypothesized that its unique biological importance and functional nonredundancy will correlate with its structure. Small-angle X-ray scattering showed that the overall shape of RIβ 2 :C 2 is different from its closest homolog, RIα 2 :C 2 . The full-length RIβ 2 :C 2 crystal structure allows us to visualize all the domains of the PKA holoenzyme complex and shows how isoform-specific assembly of holoenzyme complexes can create distinct quaternary structures even though the R 1 :C 1 heterodimers are similar in all isoforms. The creation of discrete isoform-specific PKA holoenzyme signaling "foci" paves the way for exploring further biological roles of PKA RIβ and establishes a paradigm for PKA signaling.structural biology | signal transduction | allostery C yclic AMP-dependent protein kinase (PKA) regulates a plethora of biological events that extend from development and differentiation to memory, ion transport, and metabolism. The inactive PKA holoenzyme is composed of a regulatory (R) subunit dimer and two catalytic (C) subunits. Binding of cAMP to the R-subunits unleashes the C-subunits, thereby allowing phosphorylation of PKA substrates. Specificity of PKA signaling is achieved in large part by the isoform diversity of its R-subunits. There are two classes of R-subunits, RI and RII, which are subclassified into α and β subtypes. Each isoform is encoded by a unique gene and is functionally nonredundant. RIα-null mice display early embryonic lethality (1), whereas RIIβ-null mice have a lean phenotype and are resistant to diet-induced diabetes (2). Specific isoforms also are expressed differently in cells and tissues. The RIβ isoform is expressed abundantly in brain and spinal cord (3-5). Hippocampal slices from RIβ-null mice show a severe deficit in long-term potentiation and also in long-term depression and memory. Although RIα protein levels are increased in these mice, the hippocampal function is not rescued, suggesting a unique role for RIβ, which is the least studied Rsubunit (6, 7). Most localization studies have focused on the differences between RI and RII and showed that RI isoforms are diffused mainly in the cytoplasm, whereas RIIs typically are associated with membranous organelles. More than 50 A kinase-anchoring proteins (AKAPs) have been identified as targeting PKA to a specific subcellular location (8). The only potential AKAP that binds preferentially to the RIβ isoform identified so far is the neurofibromatosis 2 tumor suppressor protein, merlin (9).All R isoforms share the same domain organization, which includes a docking and dimerization (D/D) domain followed by an inhibitor sequence and two cAMP-binding domains (Fig. 1E)....

show abstract

“…This model is based on previous structural studies of inactive PKC␦ (41). In reconstructing this model, we used the crystal structure of the C2-domain of PKC␦ (41) and the catalytic domain of PKC␤II (42), which shares substantial structural homology with PKC␦. In the closed conformation, the C2-domain is folded back upon the catalytic domain and is predicted to make extensive contacts with the region that contains the NLS.…”

Section: Regulated Binding Of Importin-␣ To Pkc␦ In Response Tomentioning

confidence: 99%

Regulated Binding of Importin-α to Protein Kinase Cδ in Response to Apoptotic Signals Facilitates Nuclear Import

Adwan

Ohm

Jones

et al. 2011

Journal of Biological Chemistry

View full text Add to dashboard Cite

Background: Tyrosine phosphorylation regulates nuclear translocation of proapoptotic protein kinase C delta (PKC␦). Results: Tyrosine phosphorylation causes a conformational change that exposes the nuclear localization sequence, allowing binding of importin-␣. Conclusion: Nuclear localization of PKC␦ is regulated by access of importin-␣ to the nuclear localization sequence. Significance: Nuclear import of PKC␦, which induces apoptosis, is tightly regulated so as to prevent inappropriate cell death.

show abstract

Crystal Structure and Allosteric Activation of Protein Kinase C βII

Cited by 169 publications

References 58 publications

Partitioning-defective Protein 6 (Par-6) Activates Atypical Protein Kinase C (aPKC) by Pseudosubstrate Displacement

Partitioning-defective Protein 6 (Par-6) Activates Atypical Protein Kinase C (aPKC) by Pseudosubstrate Displacement

Localization and quaternary structure of the PKA RIβ holoenzyme

Regulated Binding of Importin-α to Protein Kinase Cδ in Response to Apoptotic Signals Facilitates Nuclear Import

Contact Info

Product

Resources

About