PIM1

PIM1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1XQZ, 1XR1, 1XWS, 1YHS, 1YI3, 1YI4, 1YWV, 1YXS, 1YXT, 1YXU, 1YXV, 1YXX, 2BIK, 2BIL, 2BZH, 2BZI, 2BZJ, 2BZK, 2C3I, 2J2I, 2O3P, 2O63, 2O64, 2O65, 2OBJ, 2OI4, 2XIX, 2XIY, 2XIZ, 2XJ0, 2XJ1, 2XJ2, 3A99, 3BGP, 3BGQ, 3BGZ, 3BWF, 3C4E, 3CXW, 3CY2, 3CY3, 3DCV, 3F2A, 3JPV, 3JXW, 3JY0, 3JYA, 3MA3, 3QF9, 3R00, 3R01, 3R02, 3R04, 3T9I, 3UIX, 3UMW, 3UMX, 3VBQ, 3VBT, 3VBV, 3VBW, 3VBX, 3VBY, 3VC4, 3WE8, 4A7C, 4ALU, 4ALV, 4ALW, 4AS0, 4BZN, 4BZO, 4DTK, 4ENX, 4ENY, 4GW8, 4I41, 4IAA, 4JX3, 4JX7, 4K0Y, 4K18, 4K1B, 4LL5, 4LM5, 4MBI, 4MBL, 4MED, 4MTA, 4N6Y, 4N6Z, 4N70, 4RBL, 4RC2, 4RC3, 4RC4, 4RPV, 4TY1, 4WRS, 4WSY, 4WT6, 4XHK, 4XH6, 5C1Q, 5DWR, 5DIA, 5DHJ, 5DGZ, 5EOL, 5IPJ, 5IIS
Identifiers
Aliases	PIM1, PIM, Pim-1 proto-oncogene, serine/threonine kinase
External IDs	OMIM: 164960; MGI: 97584; HomoloGene: 11214; GeneCards: PIM1; OMA:PIM1 - orthologs
Gene location (Human) Chr. Chromosome 6 (human)[1] Band 6p21.2 Start 37,170,152 bp[1] End 37,175,428 bp[1]
Gene location (Mouse) Chr. Chromosome 17 (mouse)[2] Band 17 A3.3|17 15.38 cM Start 29,709,727 bp[2] End 29,715,086 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in left uterine tube gastric mucosa gallbladder blood skin of abdomen monocyte vagina bone marrow cells smooth muscle tissue appendix Top expressed in lip blood morula yolk sac thymus adrenal gland bone marrow ciliary body esophagus spleen More reference expression data BioGPS More reference expression data
Gene ontology Molecular function transferase activity nucleotide binding protein kinase activity manganese ion binding ribosomal small subunit binding transcription factor binding metal ion binding kinase activity protein serine/threonine kinase activity protein binding ATP binding Cellular component cytoplasm membrane plasma membrane nucleoplasm nucleolus cytosol nucleus Biological process phosphorylation negative regulation of apoptotic process negative regulation of DNA-binding transcription factor activity multicellular organism development protein phosphorylation hyaluronan metabolic process protein autophosphorylation cell cycle cell population proliferation vitamin D receptor signaling pathway apoptotic process regulation of mitotic cell cycle positive regulation of cardiac muscle cell proliferation positive regulation of cardioblast proliferation cytokine-mediated signaling pathway positive regulation of transcription, DNA-templated protein stabilization regulation of hematopoietic stem cell proliferation Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 5292 18712 Ensembl ENSG00000137193 ENSMUSG00000024014 UniProt P11309 P06803 RefSeq (mRNA) NM_002648 NM_001243186 NM_008842 NM_001364913 RefSeq (protein) NP_001230115 NP_002639 NP_032868 NP_001351842 Location (UCSC) Chr 6: 37.17 – 37.18 Mb Chr 17: 29.71 – 29.72 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Proto-oncogene serine/threonine-protein kinase Pim-1 is an enzyme that in humans is encoded by the PIM1 gene.^[5][6][7]

Pim-1 is a proto-oncogene which encodes for the serine/threonine kinase of the same name. The pim-1 oncogene was first described in relation to murine T-cell lymphomas, as it was the locus most frequently activated by the Moloney murine leukemia virus.^[8] Subsequently, the oncogene has been implicated in multiple human cancers, including prostate cancer, acute myeloid leukemia and other hematopoietic malignancies.^[9] Primarily expressed in spleen, thymus, bone marrow, prostate, oral epithelial, hippocampus and fetal liver cells, Pim-1 has also been found to be highly expressed in cell cultures isolated from human tumors.^[8] Pim-1 is mainly involved in cell cycle progression, apoptosis and transcriptional activation, as well as more general signal transduction pathways.^[8] Pim-1's role in oncogenic signalling has led to it becoming a widely studied target in cancer research, with numerous drug candidates under investigation which target it.^[10][11]

Gene

Located on chromosome 6 (6p21.2), the gene encompasses 5Kb of DNA, including 6 exons and 5 introns. Expression of Pim-1 has been shown to be regulated by the JAK/STAT pathway. Direct binding of transcription factors STAT3 and STAT5 to the Pim-1 promoter results in the transcription of Pim-1.^[8] The Pim-1 gene has been found to be conserved in dogs, cows, mice, rats, zebrafish and C. elegans. Pim-1 deficient mice have been shown to be phenotypically normal, indicating that there is redundancy in the function of this kinase.^[8] In fact, sequence homology searches have shown that two other Pim-1-like kinases, Pim-2 and Pim-3, are structurally and functionally similar.^[8] The Pim-1 gene encodes has multiple translation initiation sites, resulting in two proteins of 34 and 44kD.^[8]

Protein structure

Human, murine and rat Pim-1 contain 313 amino acids, and have a 94 – 97% amino acid identity.^[8] The active site of the protein, ranging from amino acids 38-290, is composed of several conserved motifs, including a glycine loop motif, a phosphate binding site and a proton acceptor site.^[8] Modification of the protein at amino acid 67 (lysine to methionine) results in the inactivation of the kinase.^[8]

Activation and stabilization

Pim-1 is primarily involved in cytokine signaling, and has been implicated in many signal transduction pathways. Because Pim-1 transcription is initiated by STAT3 and STAT5, its production is regulated by the cytokines that regulate the STAT pathway, or STAT factors. These include interleukins (IL-2, IL-3,IL-5, IL-6, IL-7, IL12, IL-15), prolactin, TNFα, EGF and IFNγ, among others.^[8] Pim-1 itself can bind to negative regulators of the JAK/STAT pathway, resulting in a negative feedback loop.

Although little is known about the post-transcriptional modifications of Pim-1, it has been hypothesized that Hsp90 is responsible for the folding and stabilization of Pim-1, although the exact mechanism has yet to be discovered.^[8] Furthermore, the serine/threonine phosphatase PP2 has been shown to degrade Pim-1.

Interactions

PIM1 has been shown to interact with:

• CBX3,^[12]
• CDC25A,^[13]
• Heat shock protein 90kDa alpha (cytosolic), member A1,^[14]
• NFATC1,^[15]
• Nuclear mitotic apparatus protein 1,^[16]
• P21,^[17]
• SND1^[18] and
• RELA.^[19]

Other known substrates/binding partners of Pim-1 include proteins involved in transcription regulation (nuclear adaptor protein p100, HP-1, PAP-1 and TRAF2 / SNX6), and regulation of the JAK/STAT pathway (SOCS1 and SOCS3).^[8] Furthermore, Pim-1 has been shown to be a cofactor for c-Myc, a transcription factor believed to regulate 15% of all genes, and their synergy has been in prostate tumorigenesis.^[20]

Pim-1 is able to phosphorylate many targets, including itself. Many of its targets are involved in cell cycle regulation.

Activates

• Cdc25C (G₁/S positive regulator): Activation results in increased G₁ → S^[8]
• Cdc25C (G₂/M positive regulator): Activation results in increased G₂ → M^[8]

Deactivates

• Bad (Pro-apoptotic protein): Deactivation results in increased cell survival^[8]
• CKI (G1/S negative regulator): Deactivation results in increased G₁ → S^[8]
• C-TAK1 (Cdc25C inhibitor): Deactivation results in increased G₂ → M^[8]

Clinical implications

Pim-1 is directly involved in the regulation of cell cycle progression and apoptosis, and has been implicated in numerous cancers including prostate cancer, Burkitt's lymphoma and oral cancer, as well as numerous hematopoietic lymphomas. Single nucleotide polymorphisms in the Pim-1 gene have been associated with increased risk for lung cancer in Korean patients, and have also been found in diffuse large cell lymphomas.^[21] As well as showing useful activity against a range of cancers,^[11] PIM kinase inhibitors have also been suggested as possible treatments for Alzheimer's disease.^[22] PIM expression is sufficient to drive resistance to anti-angiogenic agents in prostate and colon cancer models, although the mechanism is not fully elucidated.^[23] It has been suggested that a co-targeted therapeutic approach to inhibition of Pim-1 in cancer may be preferable, with suggested co-targets including the PI3K pathway and more.^[10] PIM1 expression was found to be elevated during aging and to contribute to the development of pulmonary fibrosis.^[24]

Inhibitors

A large number of small molecule inhibitors of PIM1 have been developed. Clinical trial results so far have showed promising anti-cancer activity, but side effects due to insufficient selectivity have proved problematic and research continues to find more potent and selective inhibitors for this target.^{[25][26][27][28][29][30][31][10][11]}

Examples

• AZD1208^[32]
• LGH447^[33]
• SGI-1776,^[34][35]
• TP-3654^[36]

References

Further reading