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2D Structure
Also known as: 19171-19-8, Actimid, 4-amino-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione, Cc-4047, Pomalyst, Imnovid
Molecular Formula
C13H11N3O4
Molecular Weight
273.24  g/mol
InChI Key
UVSMNLNDYGZFPF-UHFFFAOYSA-N
FDA UNII
D2UX06XLB5

Pomalidomide is an orally bioavailable derivative of thalidomide with potential immunomodulating, antiangiogenic and antineoplastic activities. Although its exact mechanism of action has yet to be fully elucidated, pomalidomide appears to inhibit TNF-alpha production, enhance the activity of T cells and natural killer (NK) cells and enhance antibody-dependent cellular cytotoxicity (ADCC). In addition, pomalidomide may inhibit tumor angiogenesis, promote cell cycle arrest in susceptible tumor cell populations, and stimulate erythropoeisis.
Pomalidomide is a Thalidomide Analog.
1 2D Structure

2D Structure

2 Identification
2.1 Computed Descriptors
2.1.1 IUPAC Name
4-amino-2-(2,6-dioxopiperidin-3-yl)isoindole-1,3-dione
2.1.2 InChI
InChI=1S/C13H11N3O4/c14-7-3-1-2-6-10(7)13(20)16(12(6)19)8-4-5-9(17)15-11(8)18/h1-3,8H,4-5,14H2,(H,15,17,18)
2.1.3 InChI Key
UVSMNLNDYGZFPF-UHFFFAOYSA-N
2.1.4 Canonical SMILES
C1CC(=O)NC(=O)C1N2C(=O)C3=C(C2=O)C(=CC=C3)N
2.2 Other Identifiers
2.2.1 UNII
D2UX06XLB5
2.3 Synonyms
2.3.1 MeSH Synonyms

1. Actimid

2. Cc 4047

3. Cc-4047

4. Cc4047

5. Imnovid

6. Pomalyst

2.3.2 Depositor-Supplied Synonyms

1. 19171-19-8

2. Actimid

3. 4-amino-2-(2,6-dioxopiperidin-3-yl)isoindoline-1,3-dione

4. Cc-4047

5. Pomalyst

6. Imnovid

7. 4-aminothalidomide

8. 4-amino-2-(2,6-dioxo-3-piperidyl)isoindoline-1,3-dione

9. Imid 3

10. 3-amino-n-(2,6-dioxo-3-piperidyl)phthalimide

11. Cc 4047

12. 1h-isoindole-1,3(2h)-dione, 4-amino-2-(2,6-dioxo-3-piperidinyl)-

13. Imid-3

14. Pomalidomide (cc-4047)

15. 4-amino-2-(2,6-dioxopiperidin-3-yl)isoindole-1,3-dione

16. (s)-pomalidomide

17. D2ux06xlb5

18. Chebi:72690

19. Mfcd12756407

20. 1,3-dioxo-2-(2,6-dioxopiperidin-3-yl)-4-aminoisoindoline

21. 4-amino-2-(2,6-dioxo-3-piperidinyl)-1h-isoindole-1,3(2h)-dione

22. 4-amino-2-(2,6-dioxopiperidin-3-yl)-1h-isoindole-1,3(2h)-dione

23. 4-amino-2-(2,6-dioxopiperidin-3-yl)-2,3-dihydro-1h-isoindole-1,3-dione

24. Pomalidomide [usan:inn]

25. Unii-d2ux06xlb5

26. Hsdb 8222

27. Pomalyst (tn)

28. Cc4047

29. Pomalidomide- Bio-x

30. Imid1

31. Pomalidomide [mi]

32. Pomalidomide [inn]

33. Pomalidomide [jan]

34. 3-amino-n-(2,6-dioxo-3-piperidyl)phthalamide

35. Pomalidomide [usan]

36. 3-aminophthalimidoglutarimide

37. Pomalidomide [vandf]

38. Mls006011261

39. Chembl43452

40. Pomalidomide [who-dd]

41. Schembl369172

42. Gtpl7348

43. Pomalidomide (jan/usan/inn)

44. Pomalidomide [ema Epar]

45. 3-aminio-phthalimido-glutarimide

46. Schembl19250920

47. Bdbm65456

48. Imid-4047

49. Cdc-394

50. Dtxsid40893458

51. Pomalidomide, >=98% (hplc)

52. S-3-amino-phthalimido-glutarimide

53. Hms3655g05

54. Hms3744k07

55. Pomalidomide [orange Book]

56. Bcp02890

57. Bcp09107

58. Cfc83849

59. Am9718

60. Nsc767909

61. Nsc775351

62. S1567

63. Akos013400288

64. Ccg-264684

65. Cs-0165

66. Db08910

67. Nsc-767909

68. Nsc-775351

69. Sb16552

70. Ncgc00346551-01

71. Ncgc00346551-03

72. Ac-26970

73. As-17905

74. Bp-24477

75. Bp164278

76. Da-21486

77. Hy-10984

78. Smr004703012

79. Sy054807

80. Bcp0726000263

81. 3-(3-amino)-phtalamido-glutarimide

82. Ft-0697903

83. P2074

84. Sw218099-2

85. D08976

86. Ab01565777_02

87. 171p198

88. Sr-01000941573

89. J-012392

90. J-514302

91. Phthalimide, 3-amino-n-(2,6-dioxo-3-piperidyl)-

92. Q7227206

93. Sr-01000941573-1

94. 4-amino-2-(2,6-dioxo(3-piperidyl))isoindoline-1,3-dione

95. 4-amino-2-(2,6-dioxo-3-piperidinyl)isoindole-1,3-dione

96. 4-amino-2-(2,6-dioxo-3-piperidyl) Isoindoline -1,3-dione

97. 4-amino-2-((3rs)-2,6-dioxopiperidin-3-yl)-1h-isoindole-1,3(2h)-dione

98. Lipopolysaccharides From Escherichia Coli 055:b5 Pound>>lipopolysaccharides Pound>> Lipoglycans Pound>>endotoxins

2.4 Create Date
2005-08-08
3 Chemical and Physical Properties
Molecular Weight 273.24 g/mol
Molecular Formula C13H11N3O4
XLogP30.2
Hydrogen Bond Donor Count2
Hydrogen Bond Acceptor Count5
Rotatable Bond Count1
Exact Mass273.07495584 g/mol
Monoisotopic Mass273.07495584 g/mol
Topological Polar Surface Area110 Ų
Heavy Atom Count20
Formal Charge0
Complexity504
Isotope Atom Count0
Defined Atom Stereocenter Count0
Undefined Atom Stereocenter Count1
Defined Bond Stereocenter Count0
Undefined Bond Stereocenter Count0
Covalently Bonded Unit Count1
4 Drug and Medication Information
4.1 Drug Information
1 of 2  
Drug NamePomalyst
PubMed HealthPomalidomide (By mouth)
Drug ClassesAntineoplastic Agent
Active IngredientPomalidomide
Dosage FormCapsule
RouteOral
Strength1mg; 4mg; 2mg; 3mg
Market StatusPrescription
CompanyCelgene

2 of 2  
Drug NamePomalyst
PubMed HealthPomalidomide (By mouth)
Drug ClassesAntineoplastic Agent
Active IngredientPomalidomide
Dosage FormCapsule
RouteOral
Strength1mg; 4mg; 2mg; 3mg
Market StatusPrescription
CompanyCelgene

4.2 Therapeutic Uses

Angiogenesis Inhibitors; Immunologic Factors

National Library of Medicine's Medical Subject Headings. Linaclotide. Online file (MeSH, 2014). Available from, as of December 18, 2014: https://www.nlm.nih.gov/mesh/2014/mesh_browser/MBrowser.html


Pomalyst is indicated for patients with multiple myeloma who have received at least two prior therapies including lenalidomide and bortezomib and have demonstrated disease progression on or within 60 days of completion of the last therapy. Approval is based on response rate. Clinical benefit, such as improvement in survival or symptoms, has not been verified. /Included in US product label/

NIH; DailyMed. Current Medication Information for Pomalyst (Pomalidomide) Capsule (Revised: May 2014). Available from, as of December 31, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2b25ef01-5c9e-11e1-b86c-0800200c9a66


EXPL THER Pomalidomide /affected/ the regulation of fetal hemoglobin (HbF) making it a potential therapeutic agent for the treatment of non-malignant hematologic disorders such as sickle cell disease (SCD) and beta-thalassemia. In vitro pomalidomide was a more potent inducer of HbF than hydroxyurea (HU), the only treatment currently approved for SCD. Pomalidomide increased the expression of genes directing the production of HbF as well as gamma- and epsilon-globin gene transcription and expression during erythroid differentiation. In an in vivo knockout transgenic mouse model of SCD, pomalidomide (10 mg/kg; 5 QD/week x 8) stimulated erythropoiesis as indicated by bone marrow hyperplasia and increased extramedullary hematopoiesis, a trend toward higher reticulocytes and significantly higher red blood cell (RBC) levels. Pomalidomide significantly increased HbF expression with a trend toward higher gamma-globin chain A levels. The pomalidomide responder rate, defined as the percentage of animals that exceeded the maximum HbF and gamma-globin chain A levels in the vehicle group, reached 67% and 78% respectively. Among responders, pomalidomide induced a nearly 2-fold increase in HbF and the increase in gamma-globin chain A levels was significant and was similar to the approved HbF-inducing agent HU.

European Medicines Agency (EMA), Committee for Medicinal Products for Human Use (CHMP), European Public Assessment Report (EPAR): Pomalidomide Celgene (Pomalidomide) p.18 (2013). Available from, as of February 20, 2015: https://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Public_assessment_report/human/002682/WC500147721.pdf


4.3 Drug Warning

/BOXED WARNING/ WARNING: EMBRYO-FETAL TOXICITY. Embryo-Fetal Toxicity: Pomalyst is contraindicated in pregnancy. Pomalyst is a thalidomide analogue. Thalidomide is a known human teratogen that causes severe birth defects or embryo-fetal death. In females of reproductive potential, obtain 2 negative pregnancy tests before starting Pomalyst treatment. Females of reproductive potential must use 2 forms of contraception or continuously abstain from heterosexual sex during and for 4 weeks after stopping Pomalyst treatment. Pomalyst is only available through a restricted distribution program called Pomalyst REMS.

NIH; DailyMed. Current Medication Information for Pomalyst (Pomalidomide) Capsule (Revised: May 2014). Available from, as of December 31, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2b25ef01-5c9e-11e1-b86c-0800200c9a66


/BOXED WARNING/ WARNING: VENOUS THROMBOEMBOLISM. Deep venous thrombosis (DVT) and pulmonary embolism (PE) occur in patients with multiple myeloma treated with Pomalyst. Prophylactic anti-thrombotic measures were employed in the clinical trial. Consider prophylactic measures after assessing an individual patient's underlying risk factors

NIH; DailyMed. Current Medication Information for Pomalyst (Pomalidomide) Capsule (Revised: May 2014). Available from, as of February 27, 2015: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2b25ef01-5c9e-11e1-b86c-0800200c9a66


Use of pomalidomide should be avoided in patients with serum aminotransferase (ALT and AST) concentrations exceeding 3 times the upper limit of normal (ULN) and bilirubin concentrations exceeding 2 mg/dL. Use of pomalidomide also should be avoided in patients with serum creatinine concentrations exceeding 3 mg/dL. Safety and efficacy have not been established in these patients.

American Society of Health-System Pharmacists 2015; Drug Information 2015. Bethesda, MD. 2015, p. 1200


Pomalidomide may cause fetal toxicity; pomalidomide is a structural analog of thalidomide, a known human teratogen, and teratogenic and other fetotoxic effects of pomalidomide (e.g., musculoskeletal anomalies and deformities; absence of internal organs, including bladder and thyroid; defects of internal organ systems, including cardiovascular, respiratory, renal, hepatic, and CNS abnormalities; increased fetal resorptions) have been demonstrated in animals. Therefore, pomalidomide is contraindicated in women who are pregnant.

American Society of Health-System Pharmacists 2015; Drug Information 2015. Bethesda, MD. 2015, p. 1200


For more Drug Warnings (Complete) data for Pomalidomide (21 total), please visit the HSDB record page.


4.4 Drug Indication

Pomalidomide is indicated for patients with multiple myeloma who have received at least two prior therapies including lenalidomide and bortezomib and have demonstrated disease progression on or within 60 days of completion of the last therapy.


FDA Label


Imnovid in combination with bortezomib and dexamethasone is indicated in the treatment of adult patients with multiple myeloma who have received at least one prior treatment regimen including lenalidomide.

Imnovid in combination with dexamethasone is indicated in the treatment of adult patients with relapsed and refractory multiple myeloma who have received at least two prior treatment regimens, including both lenalidomide and bortezomib, and have demonstrated disease progression on the last therapy.


Treatment of post-essential thrombocythaemia myelofibrosis, Treatment of post-polycythaemia vera myelofibrosis


5 Pharmacology and Biochemistry
5.1 Pharmacology

Pomalidomide is more potent than thalidomide (100-times) and lenalidomide (10-times).


5.2 MeSH Pharmacological Classification

Angiogenesis Inhibitors

Agents and endogenous substances that antagonize or inhibit the development of new blood vessels. (See all compounds classified as Angiogenesis Inhibitors.)


Immunologic Factors

Biologically active substances whose activities affect or play a role in the functioning of the immune system. (See all compounds classified as Immunologic Factors.)


5.3 FDA Pharmacological Classification
5.3.1 Active Moiety
POMALIDOMIDE
5.3.2 FDA UNII
D2UX06XLB5
5.3.3 Pharmacological Classes
Thalidomide Analog [EPC]
5.4 ATC Code

L04AX06


L04AX06

S76 | LUXPHARMA | Pharmaceuticals Marketed in Luxembourg | Pharmaceuticals marketed in Luxembourg, as published by d'Gesondheetskeess (CNS, la caisse nationale de sante, www.cns.lu), mapped by name to structures using CompTox by R. Singh et al. (in prep.). List downloaded from https://cns.public.lu/en/legislations/textes-coordonnes/liste-med-comm.html. Dataset DOI:10.5281/zenodo.4587355


L - Antineoplastic and immunomodulating agents

L04 - Immunosuppressants

L04A - Immunosuppressants

L04AX - Other immunosuppressants

L04AX06 - Pomalidomide


5.5 Absorption, Distribution and Excretion

Absorption

Pomalidomide is generally well absorbed. The major circulating component is the parent compound. Tmax, single oral dose = 2 -3 hours. When 4 mg of promalidomide is given to patients with multiple myeloma, the steady-state pharmacokinetic parameters are as follows: AUC(T) = 400 ng.hr/mL; Cmax = 75 ng/mL. Promalidomide accumulates following multiple doses.


Route of Elimination

When a single oral dose (2mg) is given to healthy subjects, 73% of the dose was eliminated in urine. 15% of the dose was eliminated in feces. 2% and 8% of the dose eliminated unchanged as pomalidomide in urine and feces, respectively.


Volume of Distribution

Mean apparent volume of distribution (Vd/F), steady-state = 62 - 138 L


Clearance

Total body clearance = 7-10 L/hour


Pomalidomide has a mean apparent volume of distribution (Vd/F) between 62 and 138 L at steady state. Pomalidomide is distributed in semen of healthy subjects at a concentration of approximately 67% of plasma level at 4 hours post-dose (approximate Tmax) after 4 days of once-daily dosing at 2 mg. Human plasma protein binding ranges from 12% to 44% and is not concentration dependent. Pomalidomide is a substrate for P-glycoprotein (P-gp).

NIH; DailyMed. Current Medication Information for Pomalyst (Pomalidomide) Capsule (Revised: May 2014). Available from, as of February 13, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2b25ef01-5c9e-11e1-b86c-0800200c9a66


In patients with multiple myeloma who received Pomalyst 4 mg daily alone or in combination with dexamethasone, pomalidomide steady-state drug exposure was characterized by AUC(T) of 400 ng*h/mL and Cmax of 75 ng/mL. Following multiple doses, pomalidomide has an accumulation ratio of 27% to 31%.

NIH; DailyMed. Current Medication Information for Pomalyst (Pomalidomide) Capsule (Revised: May 2014). Available from, as of February 13, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2b25ef01-5c9e-11e1-b86c-0800200c9a66


Following a single oral administration of (14)C-pomalidomide (2 mg) to healthy subjects, approximately 73% and 15% of the radioactive dose was eliminated in urine and feces, respectively, with approximately 2% and 8% of the radiolabeled dose eliminated unchanged as pomalidomide in urine and feces.

NIH; DailyMed. Current Medication Information for Pomalyst (Pomalidomide) Capsule (Revised: May 2014). Available from, as of February 13, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2b25ef01-5c9e-11e1-b86c-0800200c9a66


Pomalidomide has a mean total body clearance (CL/F) of 7-10 L/hr.

NIH; DailyMed. Current Medication Information for Pomalyst (Pomalidomide) Capsule (Revised: May 2014). Available from, as of February 13, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2b25ef01-5c9e-11e1-b86c-0800200c9a66


For more Absorption, Distribution and Excretion (Complete) data for Pomalidomide (12 total), please visit the HSDB record page.


5.6 Metabolism/Metabolites

Promalidomide is hepatically metabolized by CYP1A2 and CYP3A4. The metabolites are 26-fold less active than the parent compound. Minor contributions from CYP2C19 and CYP2D6 have been observed in vitro.


In hepatocytes from rabbit and human, and in vivo in rat, monkey and human, pomalidomide was metabolized primarily via hydroxylation of the phthalimide ring (M14, M16 and M17) followed by glucuronidation (M12 and M13), hydrolysis of the glutarimide ring (M10 and M11), and hydrolysis of the phthalimide ring (M2). There were no unique or disproportionate metabolites observed in humans, compared to rats and monkeys.

European Medicines Agency (EMA), Committee for Medicinal Products for Human Use (CHMP), European Public Assessment Report (EPAR): Pomalidomide Celgene (Pomalidomide) p.20 (2013). Available from, as of February 20, 2015: https://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Public_assessment_report/human/002682/WC500147721.pdf


Pomalidomide is primarily metabolized in the liver by CYP1A2 and CYP3A4. In vitro, CYP1A2 and CYP3A4 were identified as the primary enzymes involved in the CYP-mediated hydroxylation of pomalidomide, with additional minor contributions from CYP2C19 and CYP2D6.

NIH; DailyMed. Current Medication Information for Pomalyst (Pomalidomide) Capsule (Revised: May 2014). Available from, as of February 13, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2b25ef01-5c9e-11e1-b86c-0800200c9a66


5.7 Biological Half-Life

Healthy subjects = 9.4 hours; Multiple myeloma patients = 7.5 hours.


... the terminal half-lives of pomalidomide in animals ranged from mean values of 4 to 7 hours following an IV dose.

European Medicines Agency (EMA), Committee for Medicinal Products for Human Use (CHMP), European Public Assessment Report (EPAR): Pomalidomide Celgene (Pomalidomide) p.19 (2013). Available from, as of February 20, 2015: https://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Public_assessment_report/human/002682/WC500147721.pdf


Pomalidomide is eliminated with a median plasma half-life of approximately 9.5 hours in healthy subjects and approximately 7.5 hours in patients with multiple myeloma.

NIH; DailyMed. Current Medication Information for Pomalyst (Pomalidomide) Capsule (Revised: May 2014). Available from, as of February 13, 2014: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2b25ef01-5c9e-11e1-b86c-0800200c9a66


5.8 Mechanism of Action

Promalidomide is an immunomodulatory agent with antineoplastic activity. It is shown to inhibit the proliferation and induce apoptosis of various tumour cells. Furthermore, promalidomide enhances T cell and natural killer (NK) cell-mediated immunity and inhibited the production of pro-inflammatory cytokines, like TNF-alpha or IL-6, by monocytes. The primary target of promalidomide is thought to be the protein cereblon. It binds to this target and inhibits ubiquitin ligase activity. It is also a transcriptional inhibitor of COX2.


In vitro studies have identified a molecular mechanism for the pleiotropic effects of pomalidomide in multiple myeloma (MM) and in T cells. Specifically, pomalidomide bound to the protein cereblon (CRBN), part of an E3 ligase complex, and the expression levels of CRBN in myeloma cells was linked to both the efficacy of pomalidomide and to the acquisition of resistance to lenalidomide. Pomalidomide was claimed to have direct antiproliferative activity against B cell lines derived from MM and Burkitt's lymphoma patients. Pomalidomide in combination with dexamethasone increased this effect in a dose dependent manner.

European Medicines Agency (EMA), Committee for Medicinal Products for Human Use (CHMP), European Public Assessment Report (EPAR): Pomalidomide Celgene (Pomalidomide) p.16 (2013). Available from, as of February 20, 2015: https://www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Public_assessment_report/human/002682/WC500147721.pdf


Although several mechanisms have been proposed to explain the activity of thalidomide, lenalidomide and pomalidomide in multiple myeloma (MM), including demonstrable anti-angiogenic, anti-proliferative and immunomodulatory effects, the precise cellular targets and molecular mechanisms have only recently become clear. A landmark study recently identified cereblon (CRBN) as a primary target of thalidomide teratogenicity. Subsequently it was demonstrated that CRBN is also required for the anti-myeloma activity of thalidomide and related drugs, the so-called immune-modulatory drugs (IMiDs). Low CRBN expression was found to correlate with drug resistance in MM cell lines and primary MM cells. One of the downstream targets of CRBN identified is interferon regulatory factor 4 (IRF4), which is critical for myeloma cell survival and is down-regulated by IMiD treatment. CRBN is also implicated in several effects of IMiDs, such as down-regulation of tumor necrosis factor-alpha (TNF-a) and T cell immunomodulatory activity, demonstrating that the pleotropic actions of the IMiDs are initiated by binding to CRBN. Future dissection of CRBN downstream signaling will help to delineate the underlying mechanisms for IMiD action and eventually lead to development of new drugs with more specific anti-myeloma activities. It may also provide a biomarker to predict IMiD response and resistance.

PMID:22966948 Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3931443 Zhu YX et al; Leuk Lymphoma 54 (4): 683-7 (2013)


The Cul4-Rbx1-DDB1-Cereblon E3 ubiquitin ligase complex is the target of thalidomide, lenalidomide and pomalidomide, therapeutically important drugs for multiple myeloma and other B-cell malignancies. These drugs directly bind Cereblon (CRBN) and promote the recruitment of substrates Ikaros (IKZF1) and Aiolos (IKZF3) to the E3 complex, thus leading to substrate ubiquitination and degradation. Here we present the crystal structure of human CRBN bound to DDB1 and the drug lenalidomide. A hydrophobic pocket in the thalidomide-binding domain (TBD) of CRBN accommodates the glutarimide moiety of lenalidomide, whereas the isoindolinone ring is exposed to solvent. We also solved the structures of the mouse TBD in the apo state and with thalidomide or pomalidomide. Site-directed mutagenesis in lentiviral-expression myeloma models showed that key drug-binding residues are critical for antiproliferative effects.

PMID:25108355 Chamberlain PP et al; Nat Struct Mol Biol 21 (9): 803-9 (2014)


In the 1950s, the drug thalidomide, administered as a sedative to pregnant women, led to the birth of thousands of children with multiple defects. Despite the teratogenicity of thalidomide and its derivatives lenalidomide and pomalidomide, these immunomodulatory drugs (IMiDs) recently emerged as effective treatments for multiple myeloma and 5q-deletion-associated dysplasia. IMiDs target the E3 ubiquitin ligase CUL4-RBX1-DDB1-CRBN (known as CRL4(CRBN)) and promote the ubiquitination of the IKAROS family transcription factors IKZF1 and IKZF3 by CRL4(CRBN). Here we present crystal structures of the DDB1-CRBN complex bound to thalidomide, lenalidomide and pomalidomide. The structure establishes that CRBN is a substrate receptor within CRL4(CRBN) and enantioselectively binds IMiDs. Using an unbiased screen, we identified the homeobox transcription factor MEIS2 as an endogenous substrate of CRL4(CRBN). Our studies suggest that IMiDs block endogenous substrates (MEIS2) from binding to CRL4(CRBN) while the ligase complex is recruiting IKZF1 or IKZF3 for degradation. This dual activity implies that small molecules can modulate an E3 ubiquitin ligase and thereby upregulate or downregulate the ubiquitination of proteins.

PMID:25043012 Full text: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4423819 Fischer ES et al; Nature 512 (7512): 49-53 (2014)