P70-S6 Kinase 1

Last updated
RPS6KB1
Protein RPS6KB1 PDB 3A60.png
Available structures
PDB Ortholog search: PDBe RCSB
Identifiers
Aliases RPS6KB1 , PS6K, S6K, S6K-beta-1, S6K1, STK14A, p70 S6KA, p70(S6K)-alpha, p70-S6K, p70-alpha, P70-S6 Kinase 1, ribosomal protein S6 kinase B1, p70S6K, p70S6 kinase
External IDs OMIM: 608938 MGI: 1270849 HomoloGene: 81703 GeneCards: RPS6KB1
Orthologs
SpeciesHumanMouse
Entrez

6198

72508

Ensembl

ENSG00000108443

ENSMUSG00000020516

UniProt

P23443

Q8BSK8

RefSeq (mRNA)

NM_001272042
NM_001272043
NM_001272044
NM_001272060
NM_003161

NM_001114334
NM_028259
NM_001363162

RefSeq (protein)

NP_001107806
NP_082535
NP_001350091

Location (UCSC) Chr 17: 59.89 – 59.95 Mb Chr 11: 86.5 – 86.54 Mb
PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Ribosomal protein S6 kinase beta-1 (S6K1), also known as p70S6 kinase (p70S6K, p70-S6K), is an enzyme (specifically, a protein kinase) that in humans is encoded by the RPS6KB1 gene. [5] [6] It is a serine/threonine kinase that acts downstream of PIP3 and phosphoinositide-dependent kinase-1 in the PI3 kinase pathway. [7] As the name suggests, its target substrate is the S6 ribosomal protein. [8] Phosphorylation of S6 induces protein synthesis at the ribosome.

The phosphorylation of p70S6K at threonine 389 has been used as a hallmark of activation by mTOR and correlated with autophagy inhibition in various situations. However, several recent studies suggest that the activity of p70S6K plays a more positive role in the increase of autophagy. [9] [10]

Function

This gene encodes a member of the S6K family of serine/threonine kinases, which phosphorylate several residues of the S6 ribosomal protein. The kinase activity of this protein leads to an increase in protein synthesis and cell proliferation. Amplification of the region of DNA encoding this gene and overexpression of this kinase are seen in some breast cancer cell lines. Alternate translational start sites have been described and alternate transcriptional splice variants have been observed but have not been thoroughly characterized.

mTOR

The p70S6 kinase is a downstream target of mTOR (mammalian target of rapamycin) signaling, specifically mTORC1, an mTOR-containing complex characterized by the inclusion of Raptor rather than Rictor (mTORC2). mTOR can be activated via an AND-gate-like mechanism at the lysosome, integrating signals about growth factors and bioavailability of important molecules. For instance, amino acids such as arginine and leucine can trigger lysosomal recruitment of mTORC1. Once at the lysosome, mTOR can be activated by Rheb, a small, lysosomal-resident GTPase, in its GTP-bound state. Rheb GTPase activity is stimulated (and therefore capacity to activate mTOR diminished) by the upstream TSC complex, which is inhibited by IGF signalling. Thus, the AND gate consists of proper localization by sufficiency of amino acids and activation by growth factors. Once mTOR has been properly localized and activated, it can phosphorylate downstream targets such as p70S6K, 4EBP, and ULK1 which are important for regulating protein anabolic/catabolic balance.

Physical exercise activates protein synthesis via phosphorylation (activation) of p70S6K in a pathway that is dependent on mTOR, specifically mTORC1. This has been demonstrated by using an inhibitor of mTOR, rapamycin, to block an increase in muscle mass, despite increases in load (e.g., exercise). Exercise has been shown to increase levels of IGF-1 in muscle, thus inducing the IGF-1/PI3K/Akt/p70S6K signaling pathway, and thereby increasing the protein synthesis is required to build muscle.

Clinical significance

Inhibition of the S6K1 protein, or a lack of it, slows the production of adipose (fat) cells by disrupting and retarding the initial "commitment stage" of their formation. The study could have implications for the treatment of obesity. [11]

Amplification of the region of DNA encoding this gene and overexpression of this kinase are seen in some breast cancer cell lines.

Another pathway for which P70 has proposed involvement is in muscle lengthening and growing. P70 is phosphorylated by passive stretch in the soleus muscle. This may be one of many protein kinases involved in muscle building. [12]

In its inactive state, S6K1 is bound to eIF3 and detaches following phosphorylation by mTOR/Raptor. Free S6K1 is then able to phosphorylate a number of its targets, including eIF4B. [13]

Interactions

P70-S6 Kinase 1 has been shown to interact with:

See also

Related Research Articles

mTOR Mammalian protein found in humans

The mammalian target of rapamycin (mTOR), also referred to as the mechanistic target of rapamycin, and sometimes called FK506-binding protein 12-rapamycin-associated protein 1 (FRAP1), is a kinase that in humans is encoded by the MTOR gene. mTOR is a member of the phosphatidylinositol 3-kinase-related kinase family of protein kinases.

<span class="mw-page-title-main">Ribosomal s6 kinase</span>

In molecular biology, ribosomal s6 kinase (rsk) is a family of protein kinases involved in signal transduction. There are two subfamilies of rsk, p90rsk, also known as MAPK-activated protein kinase-1 (MAPKAP-K1), and p70rsk, also known as S6-H1 Kinase or simply S6 Kinase. There are three variants of p90rsk in humans, rsk 1-3. Rsks are serine/threonine kinases and are activated by the MAPK/ERK pathway. There are two known mammalian homologues of S6 Kinase: S6K1 and S6K2.

<span class="mw-page-title-main">Ribosomal protein S6</span> Protein-coding gene in the species Homo sapiens

Ribosomal protein S6 is a component of the 40S ribosomal subunit and is therefore involved in translation. Mouse model studies have shown that phosphorylation of eS6 is involved in the regulation of cell size, cell proliferation, and glucose homeostasis.

<span class="mw-page-title-main">TSC2</span> Mammalian protein found in Homo sapiens

Tuberous Sclerosis Complex 2 (TSC2), also known as Tuberin, is a protein that in humans is encoded by the TSC2 gene.

<span class="mw-page-title-main">EIF4EBP1</span> Protein-coding gene in the species Homo sapiens

Eukaryotic translation initiation factor 4E-binding protein 1 is a protein that in humans is encoded by the EIF4EBP1 gene. inhibits cap-dependent translation by binding to translation initiation factor eIF4E. phosphorylaion of 4E-BP1 results in its release from eIF4E, thereby allows cap-dependent translation to continue thereby increasing the rate of protein synthesis.

<span class="mw-page-title-main">RHEB</span> Protein-coding gene in the species Homo sapiens

RHEB also known as Ras homolog enriched in brain (RHEB) is a GTP-binding protein that is ubiquitously expressed in humans and other mammals. The protein is largely involved in the mTOR pathway and the regulation of the cell cycle.

<span class="mw-page-title-main">RPS6KA1</span> Enzyme

Ribosomal protein S6 kinase alpha-1 is an enzyme that in humans is encoded by the RPS6KA1 gene.

<span class="mw-page-title-main">Protein kinase, AMP-activated, alpha 1</span> Protein-coding gene in the species Homo sapiens

5'-AMP-activated protein kinase catalytic subunit alpha-1 is an enzyme that in humans is encoded by the PRKAA1 gene.

<span class="mw-page-title-main">RPS6KA5</span> Enzyme

Ribosomal protein S6 kinase alpha-5 is an enzyme that in humans is encoded by the RPS6KA5 gene. This kinase, together with RPS6KA4, are thought to mediate the phosphorylation of histone H3, linked to the expression of immediate early genes.

<span class="mw-page-title-main">RPS6KA2</span> Enzyme found in humans

Ribosomal protein S6 kinase alpha-2 is an enzyme that in humans is encoded by the RPS6KA2 gene.

<span class="mw-page-title-main">RPS6KB2</span> Enzyme

Ribosomal protein S6 kinase beta-2 is an enzyme that in humans is encoded by the RPS6KB2 gene.

<span class="mw-page-title-main">RPTOR</span> Protein-coding gene in humans

Regulatory-associated protein of mTOR also known as raptor or KIAA1303 is an adapter protein that is encoded in humans by the RPTOR gene. Two mRNAs from the gene have been identified that encode proteins of 1335 and 1177 amino acids long.

<span class="mw-page-title-main">EIF3B</span> Protein-coding gene in the species Homo sapiens

Eukaryotic translation initiation factor 3 subunit B (eIF3b) is a protein that in humans is encoded by the EIF3B gene.

<span class="mw-page-title-main">NEK6</span> Protein-coding gene in the species Homo sapiens

Serine/threonine-protein kinase Nek6 is an enzyme that in humans is encoded by the NEK6 gene.

<span class="mw-page-title-main">RICTOR</span> Protein-coding gene in the species Homo sapiens

Rapamycin-insensitive companion of mammalian target of rapamycin (RICTOR) is a protein that in humans is encoded by the RICTOR gene.

Tuberous sclerosis proteins 1 and 2, also known as TSC1 (hamartin) and TSC2 (tuberin), form a protein-complex. The encoding two genes are TSC1 and TSC2. The complex is known as a tumor suppressor. Mutations in these genes can cause tuberous sclerosis complex. Depending on the grade of the disease, intellectual disability, epilepsy and tumors of the skin, retina, heart, kidney and the central nervous system can be symptoms.

<span class="mw-page-title-main">MLST8</span> Protein-coding gene in humans

Target of rapamycin complex subunit LST8, also known as mammalian lethal with SEC13 protein 8 (mLST8) or TORC subunit LST8 or G protein beta subunit-like, is a protein that in humans is encoded by the MLST8 gene. It is a subunit of both mTORC1 and mTORC2, complexes that regulate cell growth and survival in response to nutrient, energy, redox, and hormonal signals. It is upregulated in several human colon and prostate cancer cell lines and tissues. Knockdown of mLST8 prevented mTORC formation and inhibited tumor growth and invasiveness.

mTOR inhibitors Class of pharmaceutical drugs

mTOR inhibitors are a class of drugs that inhibit the mechanistic target of rapamycin (mTOR), which is a serine/threonine-specific protein kinase that belongs to the family of phosphatidylinositol-3 kinase (PI3K) related kinases (PIKKs). mTOR regulates cellular metabolism, growth, and proliferation by forming and signaling through two protein complexes, mTORC1 and mTORC2. The most established mTOR inhibitors are so-called rapalogs, which have shown tumor responses in clinical trials against various tumor types.

mTORC1 Protein complex

mTORC1, also known as mammalian target of rapamycin complex 1 or mechanistic target of rapamycin complex 1, is a protein complex that functions as a nutrient/energy/redox sensor and controls protein synthesis.

mTOR Complex 2 (mTORC2) is an acutely rapamycin-insensitive protein complex formed by serine/threonine kinase mTOR that regulates cell proliferation and survival, cell migration and cytoskeletal remodeling. The complex itself is rather large, consisting of seven protein subunits. The catalytic mTOR subunit, DEP domain containing mTOR-interacting protein (DEPTOR), mammalian lethal with sec-13 protein 8, and TTI1/TEL2 complex are shared by both mTORC2 and mTORC1. Rapamycin-insensitive companion of mTOR (RICTOR), mammalian stress-activated protein kinase interacting protein 1 (mSIN1), and protein observed with rictor 1 and 2 (Protor1/2) can only be found in mTORC2. Rictor has been shown to be the scaffold protein for substrate binding to mTORC2.

References

  1. 1 2 3 GRCh38: Ensembl release 89: ENSG00000108443 - Ensembl, May 2017
  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000020516 - Ensembl, May 2017
  3. ↑ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ↑ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ↑ Grove JR, Banerjee P, Balasubramanyam A, Coffer PJ, Price DJ, Avruch J, Woodgett JR (Nov 1991). "Cloning and expression of two human p70 S6 kinase polypeptides differing only at their amino termini". Molecular and Cellular Biology. 11 (11): 5541–50. doi:10.1128/mcb.11.11.5541. PMC   361924 . PMID   1922062.
  6. ↑ "Entrez Gene: RPS6KB1 ribosomal protein S6 kinase, 70kDa, polypeptide 1".
  7. ↑ Chung J, Grammer TC, Lemon KP, Kazlauskas A, Blenis J (1994). "PDGF- and insulin-dependent pp70S6k activation mediated by phosphatidylinositol-3-OH kinase". Nature. 370 (6484): 71–75. Bibcode:1994Natur.370...71C. doi:10.1038/370071a0. PMID   8015612. S2CID   4352132.
  8. ↑ Chung J, Kuo CJ, Crabtree GR, Blenis J (1992). "Rapamycin-FKBP specifically blocks growth-dependent activation of and signaling by the 70 kd S6 protein kinases". Cell. 69 (7): 1227–1236. doi:10.1016/0092-8674(92)90643-Q. PMID   1377606. S2CID   31812410.
  9. ↑ Datan E, Shirazian A, Benjamin S, Matassov D, Tinari A, Malorni W, Lockshin RA, Garcia-Sastre A, Zakeri Z (March 2014). "mTOR/p70s6k signaling distinguishes routine, maintenance-level autophagy from autophagic cell death during influenza infection". Virology. 452–453: 175–190. doi:10.1016/j.virol.2014.01.008. PMC   4005847 . PMID   24606695.
  10. ↑ Ci Y, Shi K, An J, Yang Y, Hui K, Wu P, Shi L, Xu C (2014). "ROS inhibit autophagy by downregulating ULK1 mediated by the phosphorylation of p53 in selenite-treated NB4 cells". Cell Death and Disease. 5 (November 2014): 1–10. doi:10.1038/cddis.2014.506. PMC   4260759 . PMID   25429619.
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  12. ↑ Van Dyke JM, Bain JL, Riley DA (Jan 2014). "Stretch-activated signaling is modulated by stretch magnitude and contraction". Muscle & Nerve. 49 (1): 98–107. doi:10.1002/mus.23880. PMID   23620271. S2CID   206294774.
  13. ↑ Holz, Marina K.; Ballif, Bryan A.; Gygi, Steven P.; Blenis, John (2005). "mTOR and S6K1 Mediate Assembly of the Translation Preinitiation Complex through Dynamic Protein Interchange and Ordered Phosphorylation Events". Cell. 123 (4): 569–580. doi: 10.1016/j.cell.2005.10.024 . PMID   16286006. S2CID   11118504.
  14. ↑ Nemazanyy I, Panasyuk G, Zhyvoloup A, Panayotou G, Gout IT, Filonenko V (Dec 2004). "Specific interaction between S6K1 and CoA synthase: a potential link between the mTOR/S6K pathway, CoA biosynthesis and energy metabolism". FEBS Letters. 578 (3): 357–62. doi: 10.1016/j.febslet.2004.10.091 . PMID   15589845. S2CID   9916948.
  15. ↑ Panasyuk G, Nemazanyy I, Zhyvoloup A, Bretner M, Litchfield DW, Filonenko V, Gout IT (Oct 2006). "Nuclear export of S6K1 II is regulated by protein kinase CK2 phosphorylation at Ser-17". The Journal of Biological Chemistry. 281 (42): 31188–201. doi: 10.1074/jbc.M602618200 . PMID   16895915.
  16. ↑ Holz MK, Ballif BA, Gygi SP, Blenis J (Nov 2005). "mTOR and S6K1 mediate assembly of the translation preinitiation complex through dynamic protein interchange and ordered phosphorylation events". Cell. 123 (4): 569–80. doi: 10.1016/j.cell.2005.10.024 . PMID   16286006. S2CID   11118504.
  17. ↑ Ali SM, Sabatini DM (May 2005). "Structure of S6 kinase 1 determines whether raptor-mTOR or rictor-mTOR phosphorylates its hydrophobic motif site". The Journal of Biological Chemistry. 280 (20): 19445–8. doi: 10.1074/jbc.C500125200 . PMID   15809305.
  18. ↑ Ha SH, Kim DH, Kim IS, Kim JH, Lee MN, Lee HJ, Kim JH, Jang SK, Suh PG, Ryu SH (Dec 2006). "PLD2 forms a functional complex with mTOR/raptor to transduce mitogenic signals". Cellular Signalling. 18 (12): 2283–91. doi:10.1016/j.cellsig.2006.05.021. PMID   16837165.
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  20. ↑ Nojima H, Tokunaga C, Eguchi S, Oshiro N, Hidayat S, Yoshino K, Hara K, Tanaka N, Avruch J, Yonezawa K (May 2003). "The mammalian target of rapamycin (mTOR) partner, raptor, binds the mTOR substrates p70 S6 kinase and 4E-BP1 through their TOR signaling (TOS) motif". The Journal of Biological Chemistry. 278 (18): 15461–4. doi: 10.1074/jbc.C200665200 . PMID   12604610.
  21. ↑ Chiang GG, Abraham RT (Jul 2005). "Phosphorylation of mammalian target of rapamycin (mTOR) at Ser-2448 is mediated by p70S6 kinase". The Journal of Biological Chemistry. 280 (27): 25485–90. doi: 10.1074/jbc.M501707200 . PMID   15899889.
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  24. ↑ Long X, Lin Y, Ortiz-Vega S, Yonezawa K, Avruch J (Apr 2005). "Rheb binds and regulates the mTOR kinase". Current Biology. 15 (8): 702–13. doi: 10.1016/j.cub.2005.02.053 . PMID   15854902. S2CID   3078706.
  25. ↑ Toral-Barza L, Zhang WG, Lamison C, Larocque J, Gibbons J, Yu K (Jun 2005). "Characterization of the cloned full-length and a truncated human target of rapamycin: activity, specificity, and enzyme inhibition as studied by a high capacity assay". Biochemical and Biophysical Research Communications. 332 (1): 304–10. doi:10.1016/j.bbrc.2005.04.117. PMID   15896331.
  26. ↑ Saitoh M, Pullen N, Brennan P, Cantrell D, Dennis PB, Thomas G (May 2002). "Regulation of an activated S6 kinase 1 variant reveals a novel mammalian target of rapamycin phosphorylation site". The Journal of Biological Chemistry. 277 (22): 20104–12. doi: 10.1074/jbc.M201745200 . PMID   11914378.
  27. ↑ Kim DH, Sarbassov DD, Ali SM, King JE, Latek RR, Erdjument-Bromage H, Tempst P, Sabatini DM (Jul 2002). "mTOR interacts with raptor to form a nutrient-sensitive complex that signals to the cell growth machinery". Cell. 110 (2): 163–75. doi: 10.1016/S0092-8674(02)00808-5 . PMID   12150925. S2CID   4656930.
  28. ↑ Edinger AL, Linardic CM, Chiang GG, Thompson CB, Abraham RT (Dec 2003). "Differential effects of rapamycin on mammalian target of rapamycin signaling functions in mammalian cells". Cancer Research. 63 (23): 8451–60. PMID   14679009.
  29. ↑ Leone M, Crowell KJ, Chen J, Jung D, Chiang GG, Sareth S, Abraham RT, Pellecchia M (Aug 2006). "The FRB domain of mTOR: NMR solution structure and inhibitor design". Biochemistry. 45 (34): 10294–302. doi:10.1021/bi060976+. PMID   16922504.
  30. ↑ Takahashi T, Hara K, Inoue H, Kawa Y, Tokunaga C, Hidayat S, Yoshino K, Kuroda Y, Yonezawa K (Sep 2000). "Carboxyl-terminal region conserved among phosphoinositide-kinase-related kinases is indispensable for mTOR function in vivo and in vitro". Genes to Cells. 5 (9): 765–75. doi:10.1046/j.1365-2443.2000.00365.x. PMID   10971657. S2CID   39048740.
  31. ↑ Burnett PE, Barrow RK, Cohen NA, Snyder SH, Sabatini DM (Feb 1998). "RAFT1 phosphorylation of the translational regulators p70 S6 kinase and 4E-BP1". Proceedings of the National Academy of Sciences of the United States of America. 95 (4): 1432–7. Bibcode:1998PNAS...95.1432B. doi: 10.1073/pnas.95.4.1432 . PMC   19032 . PMID   9465032.
  32. ↑ Sarbassov DD, Sabatini DM (Nov 2005). "Redox regulation of the nutrient-sensitive raptor-mTOR pathway and complex". The Journal of Biological Chemistry. 280 (47): 39505–9. doi: 10.1074/jbc.M506096200 . PMID   16183647.
  33. ↑ Richardson CJ, Bröenstrup M, Fingar DC, Jülich K, Ballif BA, Gygi S, Blenis J (Sep 2004). "SKAR is a specific target of S6 kinase 1 in cell growth control". Current Biology. 14 (17): 1540–9. doi: 10.1016/j.cub.2004.08.061 . PMID   15341740. S2CID   12838409.
  34. ↑ Peterson RT, Desai BN, Hardwick JS, Schreiber SL (Apr 1999). "Protein phosphatase 2A interacts with the 70-kDa S6 kinase and is activated by inhibition of FKBP12-rapamycinassociated protein". Proceedings of the National Academy of Sciences of the United States of America. 96 (8): 4438–42. Bibcode:1999PNAS...96.4438P. doi: 10.1073/pnas.96.8.4438 . PMC   16350 . PMID   10200280.
  35. ↑ Bishop JD, Nien WL, Dauphinee SM, Too CK (Aug 2006). "Prolactin activates mammalian target-of-rapamycin through phosphatidylinositol 3-kinase and stimulates phosphorylation of p70S6K and 4E-binding protein-1 in lymphoma cells". The Journal of Endocrinology. 190 (2): 307–12. doi: 10.1677/joe.1.06368 . PMID   16899564.
  36. 1 2 Panasyuk G, Nemazanyy I, Filonenko V, Gout I (May 2008). "Ribosomal protein S6 kinase 1 interacts with and is ubiquitinated by ubiquitin ligase ROC1". Biochemical and Biophysical Research Communications. 369 (2): 339–43. doi:10.1016/j.bbrc.2008.02.016. PMID   18279656.
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