In the field of biochemistry, PDPK1 refers to the protein3-phosphoinositide-dependent protein kinase-1, an enzyme which is encoded by the PDPK1gene in humans.[5] It is implicated in the development and progression of melanomas.[6]
Function
PDPK1 is a master kinase, which is crucial for the activation of AKT/PKB and many other AGC kinases including PKC, S6K, SGK. An important role for PDPK1 is in the signaling pathways activated by several growth factors and hormones including insulin signaling.
Mice lacking PDPK1 die during early embryonic development, indicating that this enzyme is critical for transmitting the growth-promoting signals necessary for normal mammalian development.
Mice that are deficient in PDPK1 have a ≈40% decrease in body mass, mild glucose intolerance, and are resistant to cancer brought about by hyperactivation of the PI3K pathway (PTEN+/-).[7][8]
Plant PDK1 plays an important role in regulating PIN-mediated auxin transport, and is thus involved in various developmental processes, such as embryonic development, lateral root formation, vasculature patterning, apical hook formation, gravitropism and phototropism.[9]
Phosphatidylinositols are only required for the activation at the membrane of some substrates including AKT. PDPK1 however does not require membrane lipid binding for the efficient phosphorylation of most of its substrates in the cytosol (not at the cell membrane).
The kinase domain has three ligand binding sites; the substrate binding site, the ATP binding site, and the docking site (also known as PIF pocket). Several PDPK1 substrates including S6K and Protein kinase C, require the binding at this docking site. Small molecule allosteric activators of PDPK1 were shown to selectively inhibit activation of substrates that require docking site interaction. These compounds do not bind to the active site and allow PDPK1 to activate other substrates that do not require docking site interaction. PDPK1 is constitutively active and at present, there is no known inhibitor proteins for PDPK1.
The activation of PDPK1's main effector, AKT, is believed to require a proper orientation of the kinase and PH domains of PDPK1 and AKT at the membrane.
Interactions
Phosphoinositide-dependent kinase-1 has been shown to interact with:
^Mora A, Komander D, van Aalten DM, Alessi DR (April 2004). "PDK1, the master regulator of AGC kinase signal transduction". Semin. Cell Dev. Biol. 15 (2): 161–70. doi:10.1016/j.semcdb.2003.12.022. PMID15209375.
^ abcHodgkinson CP, Sale GJ (January 2002). "Regulation of both PDK1 and the phosphorylation of PKC-zeta and -delta by a C-terminal PRK2 fragment". Biochemistry. 41 (2): 561–9. doi:10.1021/bi010719z. PMID11781095.
^Le Good JA, Ziegler WH, Parekh DB, Alessi DR, Cohen P, Parker PJ (September 1998). "Protein kinase C isotypes controlled by phosphoinositide 3-kinase through the protein kinase PDK1". Science. 281 (5385): 2042–5. doi:10.1126/science.281.5385.2042. PMID9748166.
^ abChun J, Kwon T, Lee E, Suh PG, Choi EJ, Sun Kang S (October 2002). "The Na(+)/H(+) exchanger regulatory factor 2 mediates phosphorylation of serum- and glucocorticoid-induced protein kinase 1 by 3-phosphoinositide-dependent protein kinase 1". Biochem. Biophys. Res. Commun. 298 (2): 207–15. doi:10.1016/s0006-291x(02)02428-2. PMID12387817.
Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1–2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID8125298.
Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, Suyama A, Sugano S (1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library". Gene. 200 (1–2): 149–56. doi:10.1016/S0378-1119(97)00411-3. PMID9373149.
Le Good JA, Ziegler WH, Parekh DB, Alessi DR, Cohen P, Parker PJ (1998). "Protein kinase C isotypes controlled by phosphoinositide 3-kinase through the protein kinase PDK1". Science. 281 (5385): 2042–5. doi:10.1126/science.281.5385.2042. PMID9748166.
1h1w: HIGH RESOLUTION CRYSTAL STRUCTURE OF THE HUMAN PDK1 CATALYTIC DOMAIN
1oky: STRUCTURE OF HUMAN PDK1 KINASE DOMAIN IN COMPLEX WITH STAUROSPORINE
1okz: STRUCTURE OF HUMAN PDK1 KINASE DOMAIN IN COMPLEX WITH UCN-01
1uu3: STRUCTURE OF HUMAN PDK1 KINASE DOMAIN IN COMPLEX WITH LY333531
1uu7: STRUCTURE OF HUMAN PDK1 KINASE DOMAIN IN COMPLEX WITH BIM-2
1uu8: STRUCTURE OF HUMAN PDK1 KINASE DOMAIN IN COMPLEX WITH BIM-1
1uu9: STRUCTURE OF HUMAN PDK1 KINASE DOMAIN IN COMPLEX WITH BIM-3
1uvr: STRUCTURE OF HUMAN PDK1 KINASE DOMAIN IN COMPLEX WITH BIM-8
1w1d: CRYSTAL STRUCTURE OF THE PDK1 PLECKSTRIN HOMOLOGY (PH) DOMAIN BOUND TO INOSITOL (1,3,4,5)-TETRAKISPHOSPHATE
1w1g: CRYSTAL STRUCTURE OF THE PDK1 PLECKSTRIN HOMOLOGY (PH) DOMAIN BOUND TO DIC4-PHOSPHATIDYLINOSITOL (3,4,5)-TRISPHOSPHATE
1w1h: CRYSTAL STRUCTURE OF THE PDK1 PLECKSTRIN HOMOLOGY (PH) DOMAIN
1z5m: Crystal Structure Of N1-[3-[[5-bromo-2-[[3-[(1-pyrrolidinylcarbonyl)amino]phenyl]amino]-4-pyrimidinyl]amino]propyl]-2,2-dimethylpropanediamide Complexed with Human PDK1
2biy: STRUCTURE OF PDK1-S241A MUTANT KINASE DOMAIN