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Zhang Y, Gao H, Zhang L, Zhao Y, Qiu C, Liu X. Novel Germline KIT Variants in Families With Severe Piebaldism: Case Series and Literature Review. J Clin Lab Anal 2024; 38:e25073. [PMID: 38887855 PMCID: PMC11252829 DOI: 10.1002/jcla.25073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 06/20/2024] Open
Abstract
INTRODUCTION Piebaldism is a rare autosomal dominant disorder characterized by congenital white forelock and depigmented patches, which is most commonly caused by deleterious variants in the KIT gene. METHODS Four KIT variants were identified in a piebaldism case series by whole-exome sequencing. Functional experiments, including in vitro minigene reporter assay and enzyme-linked immunosorbent assay, were carried out to elucidate the pathogenicity of the variants. The genotype-phenotype correlation was summarized through extensive literature reviewing. RESULTS All the four cases had severe piebaldism presented with typical white forelock and diffuse depigmentation on the ventral trunk and limbs. Four germline variants at the tyrosine kinase (TK) domains of the KIT gene were identified: two novel variants c.1990+1G>A (p.Pro627_Gly664delinsArg) and c.2716T>C (p.Cys906Arg), and two known variants c.1879+1G>A (p.Gly592_Pro627delinsAla) and c.1747G>A (p.Glu583Lys). Both splicing variants caused exon skipping and inframe deletions in the TK1 domain. The missense variants resided at the TK1 and TK2 domains respectively impairing PI3K/AKT and MAPK/ERK signaling pathways, the downstream of KIT. All severe cases were associated with variants in the TK domains, eliciting a major dominant-negative mechanism of the disease. CONCLUSION Our data expand the mutation spectrum of KIT, emphasized by a dominant-negative effect of variants in the critical TK domains in severe cases. We also share the experience of prenatal diagnosis and informed reproductive choices for the affected families.
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Affiliation(s)
- Yuanyuan Zhang
- Department of Clinical GeneticsShengjing Hospital of China Medical UniversityShenyangChina
| | - Haiming Gao
- Department of Clinical GeneticsShengjing Hospital of China Medical UniversityShenyangChina
| | - Lu Zhang
- Department of Clinical GeneticsShengjing Hospital of China Medical UniversityShenyangChina
| | - Yunjing Zhao
- Department of Developmental PediatricsShengjing Hospital of China Medical UniversityShenyangChina
| | - Chuang Qiu
- Department of OrthopedicsShengjing Hospital of China Medical UniversityShenyangChina
| | - Xiaoliang Liu
- Department of Clinical GeneticsShengjing Hospital of China Medical UniversityShenyangChina
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Krimmer SG, Bertoletti N, Suzuki Y, Katic L, Mohanty J, Shu S, Lee S, Lax I, Mi W, Schlessinger J. Cryo-EM analyses of KIT and oncogenic mutants reveal structural oncogenic plasticity and a target for therapeutic intervention. Proc Natl Acad Sci U S A 2023; 120:e2300054120. [PMID: 36943885 PMCID: PMC10068818 DOI: 10.1073/pnas.2300054120] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 02/22/2023] [Indexed: 03/23/2023] Open
Abstract
The receptor tyrosine kinase KIT and its ligand stem cell factor (SCF) are required for the development of hematopoietic stem cells, germ cells, and other cells. A variety of human cancers, such as acute myeloid leukemia, gastrointestinal stromal tumor, and mast cell leukemia, are driven by somatic gain-of-function KIT mutations. Here, we report cryo electron microscopy (cryo-EM) structural analyses of full-length wild-type and two oncogenic KIT mutants, which show that the overall symmetric arrangement of the extracellular domain of ligand-occupied KIT dimers contains asymmetric D5 homotypic contacts juxtaposing the plasma membrane. Mutational analysis of KIT reveals in D5 region an "Achilles heel" for therapeutic intervention. A ligand-sensitized oncogenic KIT mutant exhibits a more comprehensive and stable D5 asymmetric conformation. A constitutively active ligand-independent oncogenic KIT mutant adopts a V-shaped conformation solely held by D5-mediated contacts. Binding of SCF to this mutant fully restores the conformation of wild-type KIT dimers, including the formation of salt bridges responsible for D4 homotypic contacts and other hallmarks of SCF-induced KIT dimerization. These experiments reveal an unexpected structural plasticity of oncogenic KIT mutants and a therapeutic target in D5.
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Affiliation(s)
- Stefan G. Krimmer
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Nicole Bertoletti
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Yoshihisa Suzuki
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Luka Katic
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Jyotidarsini Mohanty
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Sheng Shu
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Sangwon Lee
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Irit Lax
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Wei Mi
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
| | - Joseph Schlessinger
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT06520
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Nada H, Kim S, Godesi S, Lee J, Lee K. Discovery and optimization of natural-based nanomolar c-Kit inhibitors via in silico and in vitro studies. J Biomol Struct Dyn 2023; 41:11904-11915. [PMID: 36636795 DOI: 10.1080/07391102.2022.2164061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 12/24/2022] [Indexed: 01/14/2023]
Abstract
c-Kit is a receptor tyrosine kinase which is involved in intracellular signaling and mutations of c-Kit have been associated with various types of cancers. Investigations have shown that inhibition of c-Kit, using tyrosine kinase inhibitors, yielded promising results in cancer treatment marking it as a promising target for cancer therapy. However, the emerging resistance for the current therapy necessitates the development of more potent inhibitors which are not affected by these mutations. Herein, virtual screening of a library of natural-based compounds yielded three hits (2, 5 and 6) which possessed nanomolar inhibitory (2.02, 4.33 and 2.80 nM, respectively) activity when tested in vitro against c-Kit. Single point mutation docking studies showed the hits to be unaffected by the most common resistance mutation in imatinib-resistant cells, mutation of Val654. Although, the top hits exhibited around 3000 higher inhibitory potency toward c-Kit when compared to imatinib (5.4 µM), previous studies have shown that they are metabolically unstable. Fragment-based drug design approaches were then employed to enhance binding affinity of the top hit and make it more metabolically stable. Screening of the generated fragments yielded a new derivative, F1, which demonstrated stronger binding affinity, stability and binding free energy when compared to the hit compound 2.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Hossam Nada
- BK21 FOUR Team and Integrated Research Institute for Drug Development, College of Pharmacy, Dongguk University-Seoul, Goyang, Republic of Korea
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Badr University in Cairo, Cairo, Egypt
| | - Sungdo Kim
- BK21 FOUR Team and Integrated Research Institute for Drug Development, College of Pharmacy, Dongguk University-Seoul, Goyang, Republic of Korea
| | - Sreenivasulu Godesi
- BK21 FOUR Team and Integrated Research Institute for Drug Development, College of Pharmacy, Dongguk University-Seoul, Goyang, Republic of Korea
| | - Joohan Lee
- BK21 FOUR Team and Integrated Research Institute for Drug Development, College of Pharmacy, Dongguk University-Seoul, Goyang, Republic of Korea
| | - Kyeong Lee
- BK21 FOUR Team and Integrated Research Institute for Drug Development, College of Pharmacy, Dongguk University-Seoul, Goyang, Republic of Korea
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Khaddour K, Maahs L, Avila-Rodriguez AM, Maamar Y, Samaan S, Ansstas G. Melanoma Targeted Therapies beyond BRAF-Mutant Melanoma: Potential Druggable Mutations and Novel Treatment Approaches. Cancers (Basel) 2021; 13:5847. [PMID: 34831002 PMCID: PMC8616477 DOI: 10.3390/cancers13225847] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 12/24/2022] Open
Abstract
Melanomas exhibit the highest rate of somatic mutations among all different types of cancers (with the exception of BCC and SCC). The accumulation of a multimode of mutations in the driver oncogenes are responsible for the proliferative, invasive, and aggressive nature of melanomas. High-resolution and high-throughput technology has led to the identification of distinct mutational signatures and their downstream alterations in several key pathways that contribute to melanomagenesis. This has enabled the development of individualized treatments by targeting specific molecular alterations that are vital for cancer cell survival, which has resulted in improved outcomes in several cancers, including melanomas. To date, BRAF and MEK inhibitors remain the only approved targeted therapy with a high level of evidence in BRAFV600E/K mutant melanomas. The lack of approved precision drugs in melanomas, relative to other cancers, despite harboring one of the highest rates of somatic mutations, advocates for further research to unveil effective therapeutics. In this review, we will discuss potential druggable mutations and the ongoing research of novel individualized treatment approaches targeting non-BRAF mutations in melanomas.
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Affiliation(s)
- Karam Khaddour
- Division of Medical Oncology, Department of Medicine, Washington University in Saint Louis, Saint Louis, MO 63130, USA
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; (L.M.); (A.M.A.-R.)
| | - Lucas Maahs
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; (L.M.); (A.M.A.-R.)
| | - Ana Maria Avila-Rodriguez
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA; (L.M.); (A.M.A.-R.)
| | - Yazan Maamar
- Division of Hematology and Oncology, Department of Medicine, University of Tishreen Lattakia, Lattakia 2217, Syria;
| | - Sami Samaan
- Department of Medicine, American University of Beirut, Beirut 1107, Lebanon;
| | - George Ansstas
- Division of Medical Oncology, Department of Medicine, Washington University in Saint Louis, Saint Louis, MO 63130, USA
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Signaling Pathways That Regulate Normal and Aberrant Red Blood Cell Development. Genes (Basel) 2021; 12:genes12101646. [PMID: 34681039 PMCID: PMC8536016 DOI: 10.3390/genes12101646] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/11/2021] [Accepted: 10/14/2021] [Indexed: 01/19/2023] Open
Abstract
Blood cell development is regulated through intrinsic gene regulation and local factors including the microenvironment and cytokines. The differentiation of hematopoietic stem and progenitor cells (HSPCs) into mature erythrocytes is dependent on these cytokines binding to and stimulating their cognate receptors and the signaling cascades they initiate. Many of these pathways include kinases that can diversify signals by phosphorylating multiple substrates and amplify signals by phosphorylating multiple copies of each substrate. Indeed, synthesis of many of these cytokines is regulated by a number of signaling pathways including phosphoinositide 3-kinase (PI3K)-, extracellular signal related kinases (ERK)-, and p38 kinase-dependent pathways. Therefore, kinases act both upstream and downstream of the erythropoiesis-regulating cytokines. While many of the cytokines are well characterized, the nuanced members of the network of kinases responsible for appropriate induction of, and response to, these cytokines remains poorly defined. Here, we will examine the kinase signaling cascades required for erythropoiesis and emphasize the importance, complexity, enormous amount remaining to be characterized, and therapeutic potential that will accompany our comprehensive understanding of the erythroid kinome in both healthy and diseased states.
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Hapln1b, a central organizer of the extracellular matrix, modulates kit signalling to control developmental haematopoiesis. Blood Adv 2021; 5:4935-4948. [PMID: 34543380 PMCID: PMC9152995 DOI: 10.1182/bloodadvances.2020001524] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 06/30/2021] [Indexed: 11/20/2022] Open
Abstract
During early vertebrate development, hematopoietic stem and progenitor cells (HSPCs) are produced from hemogenic endothelium located in the dorsal aorta, before they migrate to a transient niche where they expand, the fetal liver and the caudal hematopoietic tissue (CHT), in mammals and zebrafish, respectively. In zebrafish, previous studies have shown that the extracellular matrix (ECM) around the aorta needs to be degraded to allow HSPCs to leave the aortic floor and reach blood circulation. However, the role of the ECM components in HSPC specification has never been addressed. We show here that hapln1b, a key component of the ECM is specifically expressed in hematopoietic sites in the zebrafish embryo. Gain- and loss-of-function experiments all resulted in the absence of HSPCs in the early embryo, showing that hapln1b is required, at the correct level, to specify HSPCs in the hemogenic endothelium. Furthermore, we show that the expression of hapln1b is necessary to maintain the integrity of the ECM through its link domain. By combining functional analyses and computer modelling, we show that kitlgb interacts with the ECM to specify HSPCs. We demonstrate that the ECM is an integral component of the microenvironment and mediates cytokine signalling that is required for HSPC specification.
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Lee E, de Paula MN, Baek S, Ta HKK, Nguyen MT, Jeong TH, Kim CJ, Jang YJ, Choe H. Novel Bacterial Production of Two Different Bioactive Forms of Human Stem-Cell Factor. Int J Mol Sci 2021; 22:ijms22126361. [PMID: 34198626 PMCID: PMC8232154 DOI: 10.3390/ijms22126361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/04/2021] [Accepted: 06/09/2021] [Indexed: 11/30/2022] Open
Abstract
Human stem-cell factor (hSCF) stimulates the survival, proliferation, and differentiation of hematopoietic cells by binding to the c-Kit receptor. Various applications of hSCF require the efficient and reliable production of hSCF. hSCF exists in three forms: as two membrane-spanning proteins hSCF248 and hSCF229 and truncated soluble N-terminal protein hSCF164. hSCF164 is known to be insoluble when expressed in Escherichia coli cytoplasm, requiring a complex refolding procedure. The activity of hSCF248 has never been studied. Here, we investigated novel production methods for recombinant hSCF164 and hSCF248 without the refolding process. To increase the solubility of hSCF164, maltose-binding protein (MBP) and protein disulfide isomerase b’a’ domain (PDIb’a’) tags were attached to the N-terminus of hSCF164. These fusion proteins were overexpressed in soluble form in the Origami 2(DE3) E. coli strain. These solubilization effects were enhanced at a low temperature. His-hSCF248, the poly-His tagged form of hSCF248, was expressed in a highly soluble form without a solubilization tag protein, which was unexpected because His-hSCF248 contains a transmembrane domain. hSCF164 was purified using affinity and ion-exchange chromatography, and His-hSCF248 was purified by ion-exchange and gel filtration chromatography. The purified proteins stimulated the proliferation of TF-1 cells. Interestingly, the EC50 value of His-hSCF248 was 1 pg/mL, 100-fold lower than 9 ng/mL hSCF164. Additionally, His-hSCF248 decreased the doubling time, increased the proportion of S and G2/M stages in the cell cycle, and increased the c-Myc expression at a 1000-fold lower concentration than hSCF164. In conclusion, His-hSCF248 was expressed in a soluble form in E. coli and had stronger activity than hSCF164. The molecular chaperone, MBP, enabled the soluble overexpression of hSCF164.
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Affiliation(s)
- Eunyoung Lee
- Department of Physiology, Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea; (E.L.); (M.N.d.P.); (S.B.); (H.K.K.T.); (M.T.N.); (T.-H.J.); (Y.J.J.)
| | - Michelle Novais de Paula
- Department of Physiology, Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea; (E.L.); (M.N.d.P.); (S.B.); (H.K.K.T.); (M.T.N.); (T.-H.J.); (Y.J.J.)
| | - Sangki Baek
- Department of Physiology, Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea; (E.L.); (M.N.d.P.); (S.B.); (H.K.K.T.); (M.T.N.); (T.-H.J.); (Y.J.J.)
| | - Huynh Kim Khanh Ta
- Department of Physiology, Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea; (E.L.); (M.N.d.P.); (S.B.); (H.K.K.T.); (M.T.N.); (T.-H.J.); (Y.J.J.)
| | - Minh Tan Nguyen
- Department of Physiology, Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea; (E.L.); (M.N.d.P.); (S.B.); (H.K.K.T.); (M.T.N.); (T.-H.J.); (Y.J.J.)
| | - Taeck-Hyun Jeong
- Department of Physiology, Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea; (E.L.); (M.N.d.P.); (S.B.); (H.K.K.T.); (M.T.N.); (T.-H.J.); (Y.J.J.)
| | - Chong Jai Kim
- Department of Pathology, Asan-Minnesota Institute for Innovating Transplantation, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea;
| | - Yeon Jin Jang
- Department of Physiology, Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea; (E.L.); (M.N.d.P.); (S.B.); (H.K.K.T.); (M.T.N.); (T.-H.J.); (Y.J.J.)
| | - Han Choe
- Department of Physiology, Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea; (E.L.); (M.N.d.P.); (S.B.); (H.K.K.T.); (M.T.N.); (T.-H.J.); (Y.J.J.)
- Correspondence: ; Tel.: +82-2-3010-4292; Fax: +82-2-3010-8148
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Engineering Stem Cell Factor Ligands with Different c-Kit Agonistic Potencies. Molecules 2020; 25:molecules25204850. [PMID: 33096693 PMCID: PMC7588011 DOI: 10.3390/molecules25204850] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/14/2020] [Accepted: 10/19/2020] [Indexed: 11/17/2022] Open
Abstract
Receptor tyrosine kinases (RTKs) are major players in signal transduction, regulating cellular activities in both normal regeneration and malignancy. Thus, many RTKs, c-Kit among them, play key roles in the function of both normal and neoplastic cells, and as such constitute attractive targets for therapeutic intervention. We thus sought to manipulate the self-association of stem cell factor (SCF), the cognate ligand of c-Kit, and hence its suboptimal affinity and activation potency for c-Kit. To this end, we used directed evolution to engineer SCF variants having different c-Kit activation potencies. Our yeast-displayed SCF mutant (SCFM) library screens identified altered dimerization potential and increased affinity for c-Kit by specific SCF-variants. We demonstrated the delicate balance between SCF homo-dimerization, c-Kit binding, and agonistic potencies by structural studies, in vitro binding assays and a functional angiogenesis assay. Importantly, our findings showed that a monomeric SCF variant exhibited superior agonistic potency vs. the wild-type SCF protein and vs. other high-affinity dimeric SCF variants. Our data showed that action of the monomeric ligands in binding to the RTK monomers and inducing receptor dimerization and hence activation was superior to that of the wild-type dimeric ligand, which has a higher affinity to RTK dimers but a lower activation potential. The findings of this study on the binding and c-Kit activation of engineered SCF variants thus provides insights into the structure–function dynamics of ligands and RTKs.
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Wang X, Karki U, Abeygunaratne H, UnnoldCofre C, Xu J. Plant cell-secreted stem cell factor stimulates expansion and differentiation of hematopoietic stem cells. Process Biochem 2020; 100:39-48. [PMID: 33071562 DOI: 10.1016/j.procbio.2020.09.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Ex vivo generation of red blood cells (RBCs) from hematopoietic stem cells (HSCs) used for blood transfusion represents one of the focuses in current regenerative medicine. However, massive production of HSCs-based RBCs requires a significant quantity of erythropoietic growth factors, making manufacturing at large scale cost prohibitive. Plant cell culture is proposed to be a promising bioproduction platform for functional human proteins in a safe and cost-efficient manner. This study exploited a proprietary technology, named HypGP engineering technology, for high-yield production of one of the key erythropoietic growth factors--stem cell factor (SCF)--in plant cell culture. Specifically, a designer hydroxyproline (Hyp)-O-glycosylated peptide (HypGP) comprised of 20 tandem repeats of the "Ser-Pro" motif, or (SP)20, was engineered at either the N-terminus or C-terminus of SCF in tobacco BY-2 cells. The (SP)20 tag dramatically increased the secreted yields of SCF up to 2.5 μg/ml. The (SP)20-tagged SCF showed bioactivity in promoting the proliferation of the TF-1 cell line, although the SCF-(SP)20 was 8.4-fold more potent than the (SP)20-SCF. Both the (SP)20-SCF and SCF-(SP)20 exhibited desired function in stimulating the expansion and differentiation of human umbilical cord blood CD34+ cells towards RBCs.
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Affiliation(s)
- Xiaoting Wang
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72401, USA.,Department of Biological Sciences, Arkansas State University, Jonesboro, AR 72401, USA
| | - Uddhab Karki
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72401, USA.,Department of Biological Sciences, Arkansas State University, Jonesboro, AR 72401, USA
| | - Hasara Abeygunaratne
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR 72401, USA
| | - Carmela UnnoldCofre
- Department of Biological Sciences, Arkansas State University, Jonesboro, AR 72401, USA
| | - Jianfeng Xu
- Arkansas Biosciences Institute, Arkansas State University, Jonesboro, AR 72401, USA.,College of Agriculture, Arkansas State University, Jonesboro, AR 72401, USA
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Mickiene G, Dalgėdienė I, Zvirblis G, Dapkunas Z, Plikusiene I, Buzavaite-Verteliene E, Balevičius Z, Rukšėnaitė A, Pleckaityte M. Human granulocyte-colony stimulating factor (G-CSF)/stem cell factor (SCF) fusion proteins: design, characterization and activity. PeerJ 2020; 8:e9788. [PMID: 32884863 PMCID: PMC7444511 DOI: 10.7717/peerj.9788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/31/2020] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF) are well-characterized vital hematopoietic growth factors that regulate hematopoiesis. G-CSF and SCF synergistically exhibit a stimulatory effect on hematopoietic progenitors. The combination of G-CSF and SCF has been used for mobilization of peripheral blood progenitor cells in cancer and non-cancerous conditions. To overcome challenges connected with the administration of two cytokines, we developed two fusion proteins composed of human SCF and human G-CSF interspaced by an alpha-helix-forming peptide linker. METHODS The recombinant proteins SCF-Lα-GCSF and GCSF-Lα-SCF were purified in three steps using an ion-exchange and mixed-mode chromatography. The purity and quantity of the proteins after each stage of purification was assessed using RP-HPLC, SDS-PAGE, and the Bradford assays. Purified proteins were identified using high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS) and the Western blot analyses. The molecular weight was determined by size exclusion HPLC (SE-HPLC). The activity of heterodimers was assessed using cell proliferation assays in vitro. The capacity of recombinant fusion proteins to stimulate the increase of the absolute neutrophil count in rats was determined in vivo. The binding kinetics of the proteins to immobilized G-CSF and SCF receptors was measured using total internal reflection ellipsometry and evaluated by a standard Langmuir kinetics model. RESULTS The novel SCF-Lα-GCSF and GCSF-Lα-SCF proteins were synthesized in Escherichia coli. The purity of the heterodimers reached >90% as determined by RP-HPLC. The identity of the proteins was confirmed using the Western blot and HPLC/ESI-MS assays. An array of multimeric forms, non-covalently associated dimers or trimers were detected in the protein preparations by SE-HPLC. Each protein induced a dose-dependent proliferative response on the cell lines. At equimolar concentration, the heterodimers retain 70-140% of the SCF monomer activity (p ≤ 0.01) in promoting the M-07e cells proliferation. The G-CSF moiety in GCSF-Lα-SCF retained 15% (p ≤ 0.0001) and in SCF-Lα-GCSF retained 34% (p ≤ 0.01) of the monomeric G-CSF activity in stimulating the growth of G-NFS-60 cells. The obtained results were in good agreement with the binding data of each moiety in the fusion proteins to their respective receptors. The increase in the absolute neutrophil count in rats caused by the SCF-Lα-GCSF protein corresponded to the increase induced by a mixture of SCF and G-CSF.
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Affiliation(s)
- Gitana Mickiene
- Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
- Profarma UAB, Vilnius, Lithuania
| | - Indrė Dalgėdienė
- Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
| | | | - Zilvinas Dapkunas
- Institute of Biotechnology, Vilnius University, Vilnius, Lithuania
- Profarma UAB, Vilnius, Lithuania
| | - Ieva Plikusiene
- Department of Physical Chemistry, Faculty of Chemistry and Geosciences, Vilnius University, Vilnius, Lithuania
| | - Ernesta Buzavaite-Verteliene
- Plasmonics and Nanophotonics Laboratory, Department of Laser Technology, Center for Physical Sciences and Technology, Vilnius, Lithuania
| | - Zigmas Balevičius
- Plasmonics and Nanophotonics Laboratory, Department of Laser Technology, Center for Physical Sciences and Technology, Vilnius, Lithuania
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Trenker R, Jura N. Receptor tyrosine kinase activation: From the ligand perspective. Curr Opin Cell Biol 2020; 63:174-185. [PMID: 32114309 PMCID: PMC7813211 DOI: 10.1016/j.ceb.2020.01.016] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 01/27/2020] [Accepted: 01/27/2020] [Indexed: 02/06/2023]
Abstract
Receptor tyrosine kinases (RTKs) are single-span transmembrane receptors in which relatively conserved intracellular kinase domains are coupled to divergent extracellular modules. The extracellular domains initiate receptor signaling upon binding to either soluble or membrane-embedded ligands. The diversity of extracellular domain structures allows for coupling of many unique signaling inputs to intracellular tyrosine phosphorylation. The combinatorial power of this receptor system is further increased by the fact that multiple ligands can typically interact with the same receptor. Such ligands often act as biased agonists and initiate distinct signaling responses via activation of the same receptor. Mechanisms behind such biased agonism are largely unknown for RTKs, especially at the level of receptor-ligand complex structure. Using recent progress in understanding the structures of active RTK signaling units, we discuss selected mechanisms by which ligands couple receptor activation to distinct signaling outputs.
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Affiliation(s)
- Raphael Trenker
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Natalia Jura
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, 94158, USA; Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, 94158, USA.
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12
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Xu WD, Huang AF, Fu L, Liu XY, Su LC. Targeting IL-34 in inflammatory autoimmune diseases. J Cell Physiol 2019; 234:21810-21816. [PMID: 31173370 DOI: 10.1002/jcp.28946] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 05/21/2019] [Accepted: 05/22/2019] [Indexed: 12/12/2022]
Abstract
Interleukin-34 (IL-34) shares a common receptor with macrophage colony-stimulating factor (M-CSF), and can bind to CSF-1R, induces lymphocytes differentiation, proliferation, and regulates the synthesis of inflammatory components. Recent findings reported aberrant expression of IL-34 in several autoimmune disorders, such as lupus, arthritis, systemic sclerosis, inflammatory bowel diseases. The functional analysis further demonstrated that IL-34 may perform significantly in these inflammatory autoimmune disorders. IL-34 might consider as a biomarker for these diseases. I hope this collection of the findings in this review will improve knowledge of the role of IL-34, and targeting IL-34 may give the potential for these autoimmune diseases.
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Affiliation(s)
- Wang-Dong Xu
- Department of Evidence-Based Medicine, Southwest Medical University, luzhou, China
| | - An-Fang Huang
- Department of Rheumatology and Immunology, Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Lu Fu
- Laboratory Animal Center, Southwest Medical University, Luzhou, China
| | - Xiao-Yan Liu
- Department of Evidence-Based Medicine, Southwest Medical University, luzhou, China
| | - Lin-Chong Su
- Department of Rheumatology and Immunology, Minda Hospital of Hubei Minzu University, Enshi, China
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13
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Raghav PK, Singh AK, Gangenahalli G. A change in structural integrity of c-Kit mutant D816V causes constitutive signaling. Mutat Res 2018; 808:28-38. [PMID: 29482074 DOI: 10.1016/j.mrfmmm.2018.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 02/07/2018] [Accepted: 02/13/2018] [Indexed: 06/08/2023]
Abstract
Several signaling pathways, ligands, and genes that regulate proliferative and self-renewal properties of the Hematopoietic Stem Cells (HSCs) have been studied meticulously. One of the signaling pathways that play a crucial role in the process of hematopoiesis is the Stem Cell Factor (SCF) mediated c-Kit pathway. The c-Kit is a Receptor Tyrosine Kinase (RTK), which is expressed in the cells including HSCs. It undergoes dimerization upon binding with its cognate ligand SCF. As a result, phosphorylation of the Juxtamembrane (JM) domain of c-Kit takes place at Tyr568 and Tyr570 residues. These phosphorylated residues become the docking sites for protein tyrosine phosphatases (PTPs) namely SHP-1 and SHP-2, which in turn cause dephosphorylation and negative regulation of the downstream signaling responsible for the cell proliferation. Interestingly, it has been reported that the mutation of c-Kit at D816V makes it independent of SCF stimulation and SHP-1/SHP-2 inhibition, thereby, causing its constitutive activation. The present study was commenced to elucidate the structural behavior of this mutation in the JM and A-loop region of c-Kit using Molecular Dynamics (MD) simulations of the wild-type and mutant c-Kit in unphosphorylated and phosphorylated states. The energy difference computed between the wild type and mutant (D816V) c-Kit, and protein-protein docking and complex analysis revealed the impact of this single residue mutation on the integrity dynamics of c-Kit that makes it independent of SHP-1/SHP-2 negative regulation.
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Affiliation(s)
- Pawan Kumar Raghav
- Division of Stem Cell and Gene Therapy Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), Brigadier S. K. Mazumdar Marg, Timarpur, Delhi, 110054, India
| | - Ajay Kumar Singh
- Division of Stem Cell and Gene Therapy Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), Brigadier S. K. Mazumdar Marg, Timarpur, Delhi, 110054, India
| | - Gurudutta Gangenahalli
- Division of Stem Cell and Gene Therapy Research, Institute of Nuclear Medicine and Allied Sciences (INMAS), Brigadier S. K. Mazumdar Marg, Timarpur, Delhi, 110054, India.
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14
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Jouenne F, Chauvot de Beauchene I, Bollaert E, Avril MF, Caron O, Ingster O, Lecesne A, Benusiglio P, Terrier P, Caumette V, Pissaloux D, de la Fouchardière A, Cabaret O, N'Diaye B, Velghe A, Bougeard G, Mann GJ, Koscielny S, Barrett JH, Harland M, Newton-Bishop J, Gruis N, Van Doorn R, Gauthier-Villars M, Pierron G, Stoppa-Lyonnet D, Coupier I, Guimbaud R, Delnatte C, Scoazec JY, Eggermont AM, Feunteun J, Tchertanov L, Demoulin JB, Frebourg T, Bressac-de Paillerets B. Germline CDKN2A/P16INK4A mutations contribute to genetic determinism of sarcoma. J Med Genet 2017; 54:607-612. [PMID: 28592523 DOI: 10.1136/jmedgenet-2016-104402] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 01/01/2023]
Abstract
BACKGROUND Sarcomas are rare mesenchymal malignancies whose pathogenesis is poorly understood; both environmental and genetic risk factors could contribute to their aetiology. METHODS AND RESULTS We performed whole-exome sequencing (WES) in a familial aggregation of three individuals affected with soft-tissue sarcoma (STS) without TP53 mutation (Li-Fraumeni-like, LFL) and found a shared pathogenic mutation in CDKN2A tumour suppressor gene. We searched for individuals with sarcoma among 474 melanoma-prone families with a CDKN2A-/+ genotype and for CDKN2A mutations in 190 TP53-negative LFL families where the index case was a sarcoma. Including the initial family, eight independent sarcoma cases carried a germline mutation in the CDKN2A/p16INK4A gene. In five out of seven formalin-fixed paraffin-embedded sarcomas, heterozygosity was lost at germline CDKN2A mutations sites demonstrating complete loss of function. As sarcomas are rare in CDKN2A/p16INK4A carriers, we searched in constitutional WES of nine carriers for potential modifying rare variants and identified three in platelet-derived growth factor receptor (PDGFRA) gene. Molecular modelling showed that two never-described variants could impact the PDGFRA extracellular domain structure. CONCLUSION Germline mutations in CDKN2A/P16INK4A, a gene known to predispose to hereditary melanoma, pancreatic cancer and tobacco-related cancers, account also for a subset of hereditary sarcoma. In addition, we identified PDGFRA as a candidate modifier gene.
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Affiliation(s)
- Fanélie Jouenne
- Département de Biologie et Pathologie Médicales, Gustave Roussy, Université Paris-Saclay, Villejuif, France
- INSERM, U1186, Université Paris-Saclay, Villejuif, France
| | | | - Emeline Bollaert
- De Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Marie-Françoise Avril
- Department of Dermatology, Assistance Publique-Hopitaux de Paris, Hopital Cochin Tarnier, Paris, France
- Faculté de Médecine, Paris 5 Descartes, Paris, France
| | - Olivier Caron
- Département de Médecine Oncologique, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | | | - Axel Lecesne
- Département de Médecine Oncologique, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Patrick Benusiglio
- Département de Médecine Oncologique, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Philippe Terrier
- Département de Biologie et Pathologie Médicales, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Vincent Caumette
- Département de Biologie et Pathologie Médicales, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Daniel Pissaloux
- Department of Pathology, Centre Leon Bérard, Lyon, Rhône-Alpes, France
| | | | - Odile Cabaret
- Département de Biologie et Pathologie Médicales, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Birama N'Diaye
- Département de Biologie et Pathologie Médicales, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Amélie Velghe
- De Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Gaelle Bougeard
- Faculty of Medicine, INSERM U1079, Normandy University, Rouen, France
- Department of Genetics, Rouen University Hospital, Normandy Centre for Genomic and personalized Medicine, Rouen, Haute-Normandie, France
| | - Graham J Mann
- Centre for Cancer Research, Weastmead Institute for Medical Research and Melanoma Institute, Sydney, New South Wales, Australia
| | - Serge Koscielny
- Service de Biostatistiques et d'Epidemiologie, Gustave Roussy, Villejuif, France
- INSERM U1018, CESP, Université Paris-Sud, Université Paris-Saclay, Villejuif, France
| | - Jennifer H Barrett
- Section of Epidemiology and Biostatistics, Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, UK
| | - Mark Harland
- Section of Epidemiology and Biostatistics, Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, UK
| | - Julia Newton-Bishop
- Section of Epidemiology and Biostatistics, Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, UK
| | - Nelleke Gruis
- Department of Dermatology, Leiden University Medical Center, Leiden, The Netherlands
| | - Remco Van Doorn
- Department of Dermatology, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Gaelle Pierron
- Institut Curie Hospital Group, Service de Génétique, Paris, France
| | | | - Isabelle Coupier
- Hopital Arnaud de Villeneuve, Service de Génétique Médicale et Oncogénétique, CHU de Montpellier, Montpellier, France
- CRCM Val d'Aurellle, INSERM U896, Montpellier, France
| | | | - Capucine Delnatte
- Unité d'Oncogénétique, Centre René Gauducheau, Nantes Saint Herblain, France
| | - Jean-Yves Scoazec
- Département de Biologie et Pathologie Médicales, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Alexander M Eggermont
- INSERM U1015 and Faculté de médecine, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Jean Feunteun
- CNRS UMR8200, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Luba Tchertanov
- Centre de Mathématiques et de leurs applications, Ecole Normale Supérieure de Cachan, Université Paris-Saclay, Cachan, France
| | | | - Thierry Frebourg
- Faculty of Medicine, INSERM U1079, Normandy University, Rouen, France
- Department of Genetics, Rouen University Hospital, Normandy Centre for Genomic and personalized Medicine, Rouen, Haute-Normandie, France
| | - Brigitte Bressac-de Paillerets
- Département de Biologie et Pathologie Médicales, Gustave Roussy, Université Paris-Saclay, Villejuif, France
- INSERM, U1186, Université Paris-Saclay, Villejuif, France
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15
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The stem cell factor (SCF)/c-KIT signalling in testis and prostate cancer. J Cell Commun Signal 2017; 11:297-307. [PMID: 28656507 DOI: 10.1007/s12079-017-0399-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 06/15/2017] [Indexed: 01/17/2023] Open
Abstract
The stem cell factor (SCF) is a cytokine that specifically binds the tyrosine kinase receptor c-KIT. The SCF/c-KIT interaction leads to receptor dimerization, activation of kinase activity and initiation of several signal transduction pathways that control cell proliferation, apoptosis, differentiation and migration in several tissues. The activity of SCF/c-KIT system is linked with the phosphatidylinositol 3-kinase (PI3-K), the Src, the Janus kinase/signal transducers and activators of transcription (JAK/STAT), the phospholipase-C (PLC-γ) and the mitogen-activated protein kinase (MAPK) pathways. Moreover, it has been reported that cancer cases display an overactivation of c-KIT due to the presence of gain-of-function mutations or receptor overexpression, which renders c-KIT a tempting target for cancer treatment. In the case of male cancers the most documented activated pathways are the PI3-K and Src, both enhancing abnormal cell proliferation. It is also known that the Src activity in prostate cancer cases depends on the presence of tr-KIT, the cytoplasmic truncated variant of c-KIT that is specifically expressed in tumour tissues and, thus, a very interesting target for drug development. The present review provides an overview of the signalling pathways activated by SCF/c-KIT and discusses the potential application of c-KIT inhibitors for treatment of testicular and prostatic cancers.
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16
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Ho CCM, Chhabra A, Starkl P, Schnorr PJ, Wilmes S, Moraga I, Kwon HS, Gaudenzio N, Sibilano R, Wehrman TS, Gakovic M, Sockolosky JT, Tiffany MR, Ring AM, Piehler J, Weissman IL, Galli SJ, Shizuru JA, Garcia KC. Decoupling the Functional Pleiotropy of Stem Cell Factor by Tuning c-Kit Signaling. Cell 2017; 168:1041-1052.e18. [PMID: 28283060 DOI: 10.1016/j.cell.2017.02.011] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 12/20/2016] [Accepted: 02/06/2017] [Indexed: 12/20/2022]
Abstract
Most secreted growth factors and cytokines are functionally pleiotropic because their receptors are expressed on diverse cell types. While important for normal mammalian physiology, pleiotropy limits the efficacy of cytokines and growth factors as therapeutics. Stem cell factor (SCF) is a growth factor that acts through the c-Kit receptor tyrosine kinase to elicit hematopoietic progenitor expansion but can be toxic when administered in vivo because it concurrently activates mast cells. We engineered a mechanism-based SCF partial agonist that impaired c-Kit dimerization, truncating downstream signaling amplitude. This SCF variant elicited biased activation of hematopoietic progenitors over mast cells in vitro and in vivo. Mouse models of SCF-mediated anaphylaxis, radioprotection, and hematopoietic expansion revealed that this SCF partial agonist retained therapeutic efficacy while exhibiting virtually no anaphylactic off-target effects. The approach of biasing cell activation by tuning signaling thresholds and outputs has applications to many dimeric receptor-ligand systems.
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Affiliation(s)
- Chia Chi M Ho
- Department of Bioengineering, Stanford University School of Engineering, 443 Via Ortega, Stanford, CA 94305, USA; Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Akanksha Chhabra
- Department of Blood and Marrow Transplantation, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Stanford Cancer Institute, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Philipp Starkl
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Department of Medicine I, Medical University of Vienna, Waehringer Guertel 18-20, 1090 Vienna, Austria
| | - Peter-John Schnorr
- Department of Blood and Marrow Transplantation, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Stanford Cancer Institute, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Stephan Wilmes
- Department of Biology, University of Osnabruck, Barbarastr. 11, 49076 Osnabruck, Germany
| | - Ignacio Moraga
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA
| | - Hye-Sook Kwon
- Department of Blood and Marrow Transplantation, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Stanford Cancer Institute, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Nicolas Gaudenzio
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
| | - Riccardo Sibilano
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
| | - Tom S Wehrman
- Primity Bio, 48383 Fremont Blvd, Suite 118, Fremont, CA 94538, USA
| | - Milica Gakovic
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA
| | - Jonathan T Sockolosky
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA
| | - Matthew R Tiffany
- Department of Pediatrics and Genetics, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA
| | - Aaron M Ring
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University School of Medicine, 299 Campus Drive, Stanford, CA 94305, USA
| | - Jacob Piehler
- Department of Biology, University of Osnabruck, Barbarastr. 11, 49076 Osnabruck, Germany
| | - Irving L Weissman
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA; Ludwig Center for Cancer Stem Cell Research and Medicine, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA; Stanford Cancer Institute, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - Stephen J Galli
- Department of Pathology, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, 299 Campus Drive, Stanford, CA 94305, USA
| | - Judith A Shizuru
- Department of Blood and Marrow Transplantation, Stanford University School of Medicine, 300 Pasteur Drive, Stanford, CA 94305, USA; Stanford Cancer Institute, Stanford University School of Medicine, 265 Campus Drive, Stanford, CA 94305, USA
| | - K Christopher Garcia
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA; Department of Structural Biology, Stanford University School of Medicine, 299 Campus Drive, Stanford, CA 94305, USA; Howard Hughes Medical Institute, Stanford University School of Medicine, 279 Campus Drive, Stanford, CA 94305, USA.
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17
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Chai M, Liu B, Sun F, Wei P, Chen P, Xu L, Luo SZ. Insights into the transmembrane helix associations of kit ligand by molecular dynamics simulation and TOXCAT. Proteins 2017; 85:1362-1370. [DOI: 10.1002/prot.25297] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 02/18/2017] [Accepted: 03/27/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Mengya Chai
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Bo Liu
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Fude Sun
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Peng Wei
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
- School of Basic Medical Science; Beijing University of Chinese Medicine; Beijing 100029 China
| | - Peng Chen
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Lida Xu
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
| | - Shi-Zhong Luo
- Beijing Key Laboratory of Bioprocess College of Life Science and Technology; Beijing, University of Chemical Technology; Beijing 100029 China
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18
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Dehbashi M, Kamali E, Vallian S. Comparative genomics of human stem cell factor (SCF). MOLECULAR BIOLOGY RESEARCH COMMUNICATIONS 2017; 6:1-11. [PMID: 28447043 PMCID: PMC5396809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Stem cell factor (SCF) is a critical protein with key roles in the cell such as hematopoiesis, gametogenesis and melanogenesis. In the present study a comparative analysis on nucleotide sequences of SCF was performed in Humanoids using bioinformatics tools including NCBI-BLAST, MEGA6, and JBrowse. Our analysis of nucleotide sequences to find closely evolved organisms with high similarity by NCBI-BLAST tools and MEGA6 showed that human and Chimpanzee (Pan troglodytes) were placed into the same cluster. By using JBrowse, we found that SCF in Neanderthal had a single copy number similar to modern human and partly conserved nucleotide sequences. Together, the results approved the gene flow and genetics similarity of SCF among human and P. troglodytes. This may suggest that during evolution, SCF gene transferred partly intact either on the basis of sequence or function from the same ancestors to P. troglodytes, the ancient human like Neanderthal, and then to the modern human.
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Affiliation(s)
| | | | - Sadeq Vallian
- Genetics Division, Department of Biology, Faculty of Science, University of Isfahan, Isfahan, Iran
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19
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Abstract
BACKGROUND SNAP-tag, a self-labeling protein tag, is commonly used for in vitro and in vivo analysis of bound target proteins. We report the first evidence that SNAP-tag could be used for ex vivo detection of enriched biological markers. METHODS Proof of concept was established for target c-kit receptor, a pathological and diagnostic marker for a variety of cancers. SNAP-tag conjugates with stem-cell factor (SCF) fusion proteins were designed and their binding and specificity was validated in vitro using flow cytometry and immunostaining. RESULTS Ex vivo diagnostic application of the fusion protein was demonstrated in comparison with anti-c-kit antibody for peripheral blood samples from leukemia patients and colorectal tissue specimens.
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20
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Distinct cellular properties of oncogenic KIT receptor tyrosine kinase mutants enable alternative courses of cancer cell inhibition. Proc Natl Acad Sci U S A 2016; 113:E4784-93. [PMID: 27482095 DOI: 10.1073/pnas.1610179113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Large genomic sequencing analysis as part of precision medicine efforts revealed numerous activating mutations in receptor tyrosine kinases, including KIT. Unfortunately, a single approach is not effective for inhibiting cancer cells or treating cancers driven by all known oncogenic KIT mutants. Here, we show that each of the six major KIT oncogenic mutants exhibits different enzymatic, cellular, and dynamic properties and responds distinctly to different KIT inhibitors. One class of KIT mutants responded well to anti-KIT antibody treatment alone or in combination with a low dose of tyrosine kinase inhibitors (TKIs). A second class of KIT mutants, including a mutant resistant to imatinib treatment, responded well to a combination of TKI with anti-KIT antibodies or to anti-KIT toxin conjugates, respectively. We conclude that the preferred choice of precision medicine treatments for cancers driven by activated KIT and other RTKs may rely on clear understanding of the dynamic properties of oncogenic mutants.
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21
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Fu R, Ding SX, Liu YI, Li LJ, Liu H, Wang HL, Zhang T, Shao ZH. Expression and function of hematopoiesis-stimulating factor receptors on the GPI - and GPI + hematopoietic stem cells of patients with paroxysmal nocturnal hemoglobinuria/aplastic anemia syndrome. Exp Ther Med 2016; 11:1668-1672. [PMID: 27168787 PMCID: PMC4840540 DOI: 10.3892/etm.2016.3163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 09/28/2015] [Indexed: 12/24/2022] Open
Abstract
Paroxysmal nocturnal hemoglobinuria/aplastic anemia (PNH/AA) syndrome presents a markedly increased population of cells deficient in glycophosphatidylinositol (GPI− cells) and signs of bone marrow failure, which requires treatment with hematopoiesis-stimulating factors, such as granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF). However, little is known about the effects of these stimulating factors on GPI− cells. In order to explore the effects of stimulating factors in PNH/AA, G-CSF receptor (CD114) and SCF receptor (CD117) expression levels on GPI+ and GPI− hematopoietic stem cells (HSCs) were measured by flow cytometry (FCM). The mean fluorescence intensity (MFI) values of signal transducer and activator of transcription 5 (STAT5) and phosphorylated (P)-STAT5 were measured in GPI+ and GPI− HSCs by FCM following stimulation with G-CSF or SCF in vitro. The expression levels of CD114 and CD117 on GPI− HSCs were significantly lower (P<0.01) than those on GPI+ HSCs in PNH/AA patients and normal controls. The MFI values of STAT5 in the GPI− and GPI+ HSCs of PNH/AA patients and normal controls were not significantly different. However, the MFI values of P-STAT5 in the GPI− HSCs of PNH/AA patients were significantly lower than those in the GPI+ HSCs of PNH/AA patients and normal controls prior to and following stimulation with G-CSF or SCF (P<0.01). The GPI− HSCs of PNH/AA patients responded poorly to stimulation by hematopoiesis-stimulating factors, which indicates that these factors can be used safely in patients with PNH/AA.
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Affiliation(s)
- Rong Fu
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Shao-Xue Ding
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Y I Liu
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Li-Juan Li
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Hui Liu
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Hong-Lei Wang
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Tian Zhang
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
| | - Zong-Hong Shao
- Department of Hematology, Tianjin Medical University General Hospital, Tianjin 300052, P.R. China
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22
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Figueira MI, Correia S, Vaz CV, Cardoso HJ, Gomes IM, Marques R, Maia CJ, Socorro S. Estrogens down-regulate the stem cell factor (SCF)/c-KIT system in prostate cells: Evidence of antiproliferative and proapoptotic effects. Biochem Pharmacol 2015; 99:73-87. [PMID: 26592659 DOI: 10.1016/j.bcp.2015.11.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 11/13/2015] [Indexed: 10/22/2022]
Abstract
The development of prostate cancer (PCa) is intimately associated with the hormonal environment, and the sex steroids estrogens have been implicated in prostate malignancy. However, if some studies identified estrogens as causative agents of PCa, others indicated that these steroids have a protective role counteracting prostate overgrowth. The tyrosine kinase receptor c-KIT and its ligand, the stem cell factor (SCF), have been associated with the control of cell proliferation/apoptosis and prostate carcinogenesis, and studies show that estrogens regulate their expression in different tissues, though, in the case of prostate this remains unknown. The present study aims to evaluate the role of 17β-estradiol (E2) in regulating the expression of SCF/c-KIT in human prostate cell lines and rat prostate, and to investigate the consequent effects on prostate cell proliferation and apoptosis. qPCR, Western Blot, and immuno(cito)histochemistry analysis showed that E2-treatment decreased the expression of SCF and c-KIT both in human prostate cells and rat prostate. Furthermore, the diminished expression of SCF/c-KIT was underpinned by the diminished prostate weight and reduced proliferation index. On the other hand, the results of TUNEL labelling, the increased activity of caspase-3, and the augmented expression of caspase-8 and Fas system in the prostate of E2-treated animals indicated augmented apoptosis in response to E2. The obtained results demonstrated that E2 down-regulated the expression of SCF/c-KIT system in prostate cells, which was associated with antiproliferative and proapoptotic effects. Moreover, these findings support the protective role of estrogens in PCa and open new perspectives on the application of estrogen-based therapies.
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Affiliation(s)
- Marília I Figueira
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Sara Correia
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Cátia V Vaz
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Henrique J Cardoso
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Inês M Gomes
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Ricardo Marques
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Cláudio J Maia
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal
| | - Sílvia Socorro
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Av. Infante D. Henrique, 6200-506 Covilhã, Portugal.
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23
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Zazo Seco C, Serrão de Castro L, van Nierop J, Morín M, Jhangiani S, Verver E, Schraders M, Maiwald N, Wesdorp M, Venselaar H, Spruijt L, Oostrik J, Schoots J, van Reeuwijk J, Lelieveld S, Huygen P, Insenser M, Admiraal R, Pennings R, Hoefsloot L, Arias-Vásquez A, de Ligt J, Yntema H, Jansen J, Muzny D, Huls G, van Rossum M, Lupski J, Moreno-Pelayo M, Kunst H, Kremer H, Kremer H. Allelic Mutations of KITLG, Encoding KIT Ligand, Cause Asymmetric and Unilateral Hearing Loss and Waardenburg Syndrome Type 2. Am J Hum Genet 2015; 97:647-60. [PMID: 26522471 DOI: 10.1016/j.ajhg.2015.09.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 09/24/2015] [Indexed: 01/04/2023] Open
Abstract
Linkage analysis combined with whole-exome sequencing in a large family with congenital and stable non-syndromic unilateral and asymmetric hearing loss (NS-UHL/AHL) revealed a heterozygous truncating mutation, c.286_303delinsT (p.Ser96Ter), in KITLG. This mutation co-segregated with NS-UHL/AHL as a dominant trait with reduced penetrance. By screening a panel of probands with NS-UHL/AHL, we found an additional mutation, c.200_202del (p.His67_Cys68delinsArg). In vitro studies revealed that the p.His67_Cys68delinsArg transmembrane isoform of KITLG is not detectable at the cell membrane, supporting pathogenicity. KITLG encodes a ligand for the KIT receptor. Also, KITLG-KIT signaling and MITF are suggested to mutually interact in melanocyte development. Because mutations in MITF are causative of Waardenburg syndrome type 2 (WS2), we screened KITLG in suspected WS2-affected probands. A heterozygous missense mutation, c.310C>G (p.Leu104Val), that segregated with WS2 was identified in a small family. In vitro studies revealed that the p.Leu104Val transmembrane isoform of KITLG is located at the cell membrane, as is wild-type KITLG. However, in culture media of transfected cells, the p.Leu104Val soluble isoform of KITLG was reduced, and no soluble p.His67_Cys68delinsArg and p.Ser96Ter KITLG could be detected. These data suggest that mutations in KITLG associated with NS-UHL/AHL have a loss-of-function effect. We speculate that the mechanism of the mutation underlying WS2 and leading to membrane incorporation and reduced secretion of KITLG occurs via a dominant-negative or gain-of-function effect. Our study unveils different phenotypes associated with KITLG, previously associated with pigmentation abnormalities, and will thereby improve the genetic counseling given to individuals with KITLG variants.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Hannie Kremer
- Hearing & Genes Division, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen 6525GA, the Netherlands; The Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen 6525GA, the Netherlands; Department of Human Genetics, Radboud University Medical Center, Nijmegen 6525GA, the Netherlands.
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24
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Targeting c-kit receptor in neuroblastomas and colorectal cancers using stem cell factor (SCF)-based recombinant bacterial toxins. Appl Microbiol Biotechnol 2015; 100:263-77. [DOI: 10.1007/s00253-015-6978-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/20/2015] [Accepted: 09/01/2015] [Indexed: 11/27/2022]
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25
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Berenstein R. Class III Receptor Tyrosine Kinases in Acute Leukemia - Biological Functions and Modern Laboratory Analysis. Biomark Insights 2015; 10:1-14. [PMID: 26309392 PMCID: PMC4527365 DOI: 10.4137/bmi.s22433] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/02/2015] [Accepted: 07/04/2015] [Indexed: 12/12/2022] Open
Abstract
Acute myeloid leukemia (AML) is a complex disease caused by deregulation of multiple signaling pathways. Mutations in class III receptor tyrosine kinases (RTKs) have been implicated in alteration of cell signals concerning the growth and differentiation of leukemic cells. Point mutations, insertions, or deletions of RTKs as well as chromosomal translocations induce constitutive activation of the receptor, leading to uncontrolled proliferation of undifferentiated myeloid blasts. Aberrations can occur in all domains of RTKs causing either the ligand-independent activation or mimicking the activated conformation. The World Health Organization recommended including RTK mutations in the AML classification since their detection in routine laboratory diagnostics is a major factor for prognostic stratification of patients. Polymerase chain reaction (PCR)-based methods are well-validated for the detection of fms-related tyrosine kinase 3 (FLT3) mutations and can easily be applied for other RTKs. However, when methodological limitations are reached, accessory techniques can be applied. For a higher resolution and more quantitative approach compared to agarose gel electrophoresis, PCR fragments can be separated by capillary electrophoresis. Furthermore, high-resolution melting and denaturing high-pressure liquid chromatography are reliable presequencing screening methods that reduce the sample amount for Sanger sequencing. Because traditional DNA sequencing is time-consuming, next-generation sequencing (NGS) is an innovative modern possibility to analyze a high amount of samples simultaneously in a short period of time. At present, standardized procedures for NGS are not established, but when this barrier is resolved, it will provide a new platform for rapid and reliable laboratory diagnostic of RTK mutations in patients with AML. In this article, the biological and physiological role of RTK mutations in AML as well as possible laboratory methods for their detection will be reviewed.
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Affiliation(s)
- Rimma Berenstein
- Department of Hematology, Oncology and Tumourimmunology, Charité Universitätsmedizin Berlin, Berlin, Germany
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26
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Abstract
Deranged pathway activation and KIT mutations occur in numerous solid and haematological malignancies, with gain-of-function mutations being the most common demonstrable abnormality. Through a complex series of interactions, activation of the KIT receptor tyrosine kinase leads to cell survival, evasion of apoptosis, angiogenesis, dysregulated cell cycle control and promotion of tumourigenesis. The KIT receptor tyrosine kinase is a well-studied therapeutic target in human malignancies. The KIT mutational status of a neoplasm plays an important role in predicting the response to targeted therapies. In this article we outline the structure, function and mutations of the KIT gene, its role in various neoplasms, therapeutic impacts and the role that these play in clinical patient outcome.
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Affiliation(s)
- Riyaadh Roberts
- Division of Anatomical Pathology, University of Cape Town and National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa
| | - Dhirendra Govender
- Division of Anatomical Pathology, University of Cape Town and National Health Laboratory Service, Groote Schuur Hospital, Cape Town, South Africa
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27
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Cardoso HJ, Figueira MI, Correia S, Vaz CV, Socorro S. The SCF/c-KIT system in the male: Survival strategies in fertility and cancer. Mol Reprod Dev 2014; 81:1064-79. [PMID: 25359157 DOI: 10.1002/mrd.22430] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/25/2014] [Indexed: 12/18/2022]
Abstract
Maintaining the delicate balance between cell survival and death is of the utmost importance for the proper development of germ cells and subsequent fertility. On the other hand, the fine regulation of tissue homeostasis by mechanisms that control cell fate is a factor that can prevent carcinogenesis. c-KIT is a type III receptor tyrosine kinase activated by its ligand, stem cell factor (SCF). c-KIT signaling plays a crucial role in cell fate decisions, specifically controlling cell proliferation, differentiation, survival, and apoptosis. Indeed, deregulating the SCF/c-KIT system by attenuation or overactivation of its signaling strength is linked to male infertility and cancer, and rebalancing its activity via c-KIT inhibitors has proven beneficial in treating human tumors that contain gain-of-function mutations or overexpress c-KIT. This review addresses the roles of SCF and c-KIT in the male reproductive tract, and discusses the potential application of c-KIT target therapies in disorders of the reproductive system.
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Affiliation(s)
- Henrique J Cardoso
- CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal
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28
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Figueira MI, Cardoso HJ, Correia S, Maia CJ, Socorro S. Hormonal regulation of c-KIT receptor and its ligand: implications for human infertility? ACTA ACUST UNITED AC 2014; 49:1-19. [DOI: 10.1016/j.proghi.2014.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 09/01/2014] [Indexed: 10/24/2022]
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Full-length recombinant human SCF1-165 is more thermostable than the truncated SCF1-141 form. PLoS One 2014; 9:e103251. [PMID: 25061857 PMCID: PMC4111497 DOI: 10.1371/journal.pone.0103251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 06/28/2014] [Indexed: 11/19/2022] Open
Abstract
Human stem cell factor initiates a diverse array of cellular responses, including hematopoiesis, cell proliferation, differentiation, migration and survival. To explore the relationship between its structure and function, we produced recombinant soluble human stem cell factor1–165 (wild type) and human stem cell factor1–141 (C-terminal truncated) in a yeast expression system and compared their biological activities and thermal stabilities. The biological activity of the two proteins was measured as a function of TF-1 cell viability and effects on downstream signaling targets after incubation. We found that these proteins enhanced cell viability and downstream signaling to a similar extent, in a dose-dependent manner. The biological activity of recombinant human stem cell factor1–165 was significantly greater than that of recombinant human stem cell factor1–141 after heating the proteins (100 ng/mL) at 25–110°C for 10 minutes (P<0.05 for all temperatures). In addition, circular dichroism spectral analysis indicated that β-sheet structures were altered in recombinant human stem cell factor1–141 but not recombinant human stem cell factor1–165 after heating at 90°C for 15 or 30 min. Molecular modeling and limited proteolytic digestion were also used to compare the thermo stability between human stem cell factor1–165 and human stem cell factor1–141. Together, these data indicate that stem cell factor1–165 is more thermostable than stem cell factor1–141.
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30
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Structure, domain organization, and different conformational states of stem cell factor-induced intact KIT dimers. Proc Natl Acad Sci U S A 2014; 111:1772-7. [PMID: 24449920 DOI: 10.1073/pnas.1323254111] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Using electron microscopy and fitting of crystal structures, we present the 3D reconstruction of ligand-induced dimers of intact receptor tyrosine kinase, KIT. We observe that KIT protomers form close contacts throughout the entire structure of ligand-bound receptor dimers, and that the dimeric receptors adopt multiple, defined conformational states. Interestingly, the homotypic interactions in the membrane proximal Ig-like domain of the extracellular region differ from those observed in the crystal structure of the unconstrained extracellular regions. We observe two prevalent conformations in which the tyrosine kinase domains interact asymmetrically. The asymmetric arrangement of the cytoplasmic regions may represent snapshots of molecular interactions occurring during trans autophosphorylation. Moreover, the asymmetric arrangements may facilitate specific intermolecular interactions necessary for trans phosphorylation of different KIT autophosphorylation sites that are required for stimulation of kinase activity and recruitment of signaling proteins by activated KIT.
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31
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Yao K, Lau SW, Ge W. Differential regulation of Kit ligand A expression in the ovary by IGF-I via different pathways. Mol Endocrinol 2014; 28:138-50. [PMID: 24243489 PMCID: PMC5426649 DOI: 10.1210/me.2013-1186] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 10/30/2013] [Indexed: 11/19/2022] Open
Abstract
Kit ligand (KITL) plays indispensable roles both in primordial follicle activation and in the maintenance of meiotic arrest of the oocyte. The regulation of KITL expression in the ovary, however, remains largely unknown. In the zebrafish, there are 2 paralogues of KITL, kitlga and kitlgb, and 2 Kit receptors, kita and kitb. Consistent with the situation in mammals, kitlga is only expressed in the ovarian follicle cells, and its cognate receptor kita is expressed in the oocyte. In the present study, we demonstrated that the expression of kitlga was promoted by IGF-I through its receptor IGF-IR. The stimulation involved transcription but not translation, suggesting that the kitlga gene is likely a direct downstream target of IGF-I signaling. Further experiments showed that the stimulatory effect of IGF-I was mediated by phosphatidyl inositol 3-kinase (PI3K)-Akt pathway. IGF-I also activated MEK-ERK pathway; however, this pathway suppressed kitlga expression. The regulation of kitlga expression by IGF-I appeared to depend on the stage of follicle development with a greater induction at early stage than late stage. This may be related to changes in IGF-I signaling pathways and/or local paracrine environment. In support of this were the differential expression of IGF-I receptors (igf1ra and igf1rb) and responsiveness of IGF-I signaling pathways, especially the PI3K-Akt pathway. Furthermore, the IGF-I-induced kitlga expression was inhibited by epidermal growth factor, an oocyte-derived paracrine factor in the zebrafish follicle. This study provides evidence for a controlling mechanism underlying the regulation of KITL expression in the ovary.
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Affiliation(s)
- Kai Yao
- School of Life Sciences (K.Y., S.-W.L, W.G.) and Centre for Cell and Developmental Biology (W.G.), The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China; and Faculty of Health Sciences (W.G.), University of Macau, Taipa, Macau, China
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32
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Huang Z, Ruan HB, Zhang ZD, Chen W, Lin Z, Zeng H, Gao X. Mutation in the first Ig-like domain of Kit leads to JAK2 activation and myeloproliferation in mice. THE AMERICAN JOURNAL OF PATHOLOGY 2013; 184:122-32. [PMID: 24211109 DOI: 10.1016/j.ajpath.2013.09.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 09/10/2013] [Accepted: 09/23/2013] [Indexed: 11/19/2022]
Abstract
Myeloproliferative neoplasms constitute a group of hematopoietic neoplasms at the myeloid stem cell level. Although mutations in the receptor tyrosine kinase KIT have been identified in patients with myeloproliferative neoplasm, the functional causality is unknown because of a lack of animal models. Here, we describe a mouse strain harboring a point mutation in the first Ig-like domain of Kit. Intriguingly, the mutant mice develop a myeloproliferative disorder with typical loss-of-function phenotypes in other tissues. The mutant Kit is incompletely N-glycosylated, shows compromised receptor dimerization, and down-regulates Akt and extracellular signal-regulating kinase 1/2 signaling. However, the mutation increases the association of Kit to Janus kinase (JAK)2 and hence the activation of JAK2. The β common receptor of the gp140 family interacts and synergizes with Kit to promote JAK2 phosphorylation, which is further enhanced by the Kit mutation. Inhibition of JAK2 suppresses the proliferation of hematopoietic progenitors in vitro and partially rescues myeloproliferation in mice. Our data suggest that overactivation of JAK2 leads to myeloproliferation in Kit mutant mice and provide mechanistic insights for the diagnosis and treatment of myeloproliferative neoplasms in humans.
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Affiliation(s)
- Zan Huang
- MOE Key Lab of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Hai-Bin Ruan
- MOE Key Lab of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Zeng-Di Zhang
- Nanjing Children's Hospital Affiliated to Nanjing Medical University, Nanjing, China
| | - Weiqian Chen
- MOE Key Lab of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China; Institute for Cardiovascular Science, Soochow University, Suzhou, China; Department of Cardiovascular Surgery, the First Affiliated Hospital of Soochow University, Suzhou, China
| | - Zhaoyu Lin
- MOE Key Lab of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Hu Zeng
- MOE Key Lab of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China
| | - Xiang Gao
- MOE Key Lab of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, China.
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33
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Structural basis for KIT receptor tyrosine kinase inhibition by antibodies targeting the D4 membrane-proximal region. Proc Natl Acad Sci U S A 2013; 110:17832-7. [PMID: 24127596 DOI: 10.1073/pnas.1317118110] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Somatic oncogenic mutations in the receptor tyrosine kinase KIT function as major drivers of gastrointestinal stromal tumors and a subset of acute myeloid leukemia, melanoma, and other cancers. Although treatment of these cancers with tyrosine kinase inhibitors shows dramatic responses and durable disease control, drug resistance followed by clinical progression of disease eventually occurs in virtually all patients. In this report, we describe inhibitory KIT antibodies that bind to the membrane-proximal Ig-like D4 of KIT with significant overlap with an epitope in D4 that mediates homotypic interactions essential for KIT activation. Crystal structures of the anti-KIT antibody in complex with KIT D4 and D5 allowed design of affinity-matured libraries that were used to isolate variants with increased affinity and efficacy. Isolated antibodies showed KIT inhibition together with suppression of cell proliferation driven by ligand-stimulated WT or constitutively activated oncogenic KIT mutant. These antibodies represent a unique therapeutic approach and a step toward the development of "naked" or toxin-conjugated KIT antibodies for the treatment of KIT-driven cancers.
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34
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Heldin CH, Lennartsson J. Structural and functional properties of platelet-derived growth factor and stem cell factor receptors. Cold Spring Harb Perspect Biol 2013; 5:a009100. [PMID: 23906712 DOI: 10.1101/cshperspect.a009100] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The receptors for platelet-derived growth factor (PDGF) and stem cell factor (SCF) are members of the type III class of PTK receptors, which are characterized by five Ig-like domains extracellularly and a split kinase domain intracellularly. The receptors are activated by ligand-induced dimerization, leading to autophosphorylation on specific tyrosine residues. Thereby the kinase activities of the receptors are activated and docking sites for downstream SH2 domain signal transduction molecules are created; activation of these pathways promotes cell growth, survival, and migration. These receptors mediate important signals during the embryonal development, and control tissue homeostasis in the adult. Their overactivity is seen in malignancies and other diseases involving excessive cell proliferation, such as atherosclerosis and fibrotic diseases. In cancer, mutations of PDGF and SCF receptors-including gene fusions, point mutations, and amplifications-drive subpopulations of certain malignancies, such as gastrointestinal stromal tumors, chronic myelomonocytic leukemia, hypereosinophilic syndrome, glioblastoma, acute myeloid leukemia, mastocytosis, and melanoma.
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Affiliation(s)
- Carl-Henrik Heldin
- Ludwig Institute for Cancer Research, Uppsala University, SE-751 24 Uppsala, Sweden.
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35
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Yao K, Ge W. Spatial distribution and receptor specificity of zebrafish Kit system--evidence for a Kit-mediated bi-directional communication system in the preovulatory ovarian follicle. PLoS One 2013; 8:e56192. [PMID: 23409152 PMCID: PMC3568072 DOI: 10.1371/journal.pone.0056192] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 01/07/2013] [Indexed: 01/28/2023] Open
Abstract
Consisting of Kit ligand and receptor Kit, the Kit system is involved in regulating many ovarian functions such as follicle activation, granulosa cell proliferation, and oocyte growth and maturation. In mammals, Kit ligand is derived from the granulosa cells and Kit receptor is expressed in the oocyte and theca cells. In the zebrafish, the Kit system contains two ligands (Kitlga and Kitlgb) and two receptors (Kita and Kitb). Interestingly, Kitlga and Kitb are localized in the somatic follicle cells, but Kitlgb and Kita are expressed in the oocyte. Using recombinant zebrafish Kitlga and Kitlgb, we demonstrated that Kitlga preferentially activated Kita whereas Kitlgb specifically activated Kitb by Western analysis for receptor phosphorylation. In support of this, Kitlgb triggered a stronger and longer MAPK phosphorylation in follicle cells than Kitlga, whereas Kitlga but not Kitlgb activated MAPK in the denuded oocytes, in agreement with the distribution of Kita and Kitb in the follicle and their specificity for Kitlga and Kitlgb. Further analysis of the interaction between Kit ligands and receptors by homology modeling showed that Kitlga-Kita and Kitlgb-Kitb both have more stable electrostatic interaction than Kitlgb-Kita or Kitlga-Kitb. A functional study of Kit involvement in final oocyte maturation showed that Kitlga and Kitlgb both suppressed the spontaneous maturation significantly; in contrast, Kitlgb but not Kitlga significantly promoted 17α, 20β-dihydroxy-4-pregnen-3-one (DHP) -induced oocyte maturation. Our results provided strong evidence for a Kit-mediated bi-directional communication system in the zebrafish ovarian follicle, which could be part of the complex interplay between the oocyte and the follicle cells in the development of follicles.
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Affiliation(s)
- Kai Yao
- School of Life Sciences and Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
| | - Wei Ge
- School of Life Sciences and Centre for Cell and Developmental Biology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China
- * E-mail:
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36
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Verstraete K, Savvides SN. Extracellular assembly and activation principles of oncogenic class III receptor tyrosine kinases. Nat Rev Cancer 2012; 12:753-66. [PMID: 23076159 DOI: 10.1038/nrc3371] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Intracellular signalling cascades initiated by class III receptor tyrosine kinases (RTK-IIIs) and their cytokine ligands contribute to haematopoiesis and mesenchymal tissue development. They are also implicated in a wide range of inflammatory disorders and cancers. Recent snapshots of RTK-III ectodomains in complex with cognate cytokines have revealed timely insights into the structural determinants of RTK-III activation, evolution and pathology. Importantly, candidate 'driver' and 'passenger' mutations that have been identified in RTK-IIIs can now be collectively mapped for the first time to structural scaffolds of the corresponding RTK-III ectodomains. Such insights will generate a renewed interest in dissecting the mechanistic effects of such mutations and their therapeutic relevance.
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Affiliation(s)
- Kenneth Verstraete
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium.
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Lennartsson J, Rönnstrand L. Stem Cell Factor Receptor/c-Kit: From Basic Science to Clinical Implications. Physiol Rev 2012; 92:1619-49. [DOI: 10.1152/physrev.00046.2011] [Citation(s) in RCA: 485] [Impact Index Per Article: 40.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Stem cell factor (SCF) is a dimeric molecule that exerts its biological functions by binding to and activating the receptor tyrosine kinase c-Kit. Activation of c-Kit leads to its autophosphorylation and initiation of signal transduction. Signaling proteins are recruited to activated c-Kit by certain interaction domains (e.g., SH2 and PTB) that specifically bind to phosphorylated tyrosine residues in the intracellular region of c-Kit. Activation of c-Kit signaling has been found to mediate cell survival, migration, and proliferation depending on the cell type. Signaling from c-Kit is crucial for normal hematopoiesis, pigmentation, fertility, gut movement, and some aspects of the nervous system. Deregulated c-Kit kinase activity has been found in a number of pathological conditions, including cancer and allergy. The observation that gain-of-function mutations in c-Kit can promote tumor formation and progression has stimulated the development of therapeutics agents targeting this receptor, e.g., the clinically used inhibitor imatinib mesylate. Also other clinically used multiselective kinase inhibitors, for instance, sorafenib and sunitinib, have c-Kit included in their range of targets. Furthermore, loss-of-function mutations in c-Kit have been observed and shown to give rise to a condition called piebaldism. This review provides a summary of our current knowledge regarding structural and functional aspects of c-Kit signaling both under normal and pathological conditions, as well as advances in the development of low-molecular-weight molecules inhibiting c-Kit function.
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Affiliation(s)
- Johan Lennartsson
- Ludwig Institute for Cancer Research, Uppsala University, Uppsala, Sweden; and Experimental Clinical Chemistry, Wallenberg Laboratory, Department of Laboratory Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
| | - Lars Rönnstrand
- Ludwig Institute for Cancer Research, Uppsala University, Uppsala, Sweden; and Experimental Clinical Chemistry, Wallenberg Laboratory, Department of Laboratory Medicine, Lund University, Skåne University Hospital, Malmö, Sweden
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Saravanaperumal SA, Pediconi D, Renieri C, La Terza A. Skipping of exons by premature termination of transcription and alternative splicing within intron-5 of the sheep SCF gene: a novel splice variant. PLoS One 2012; 7:e38657. [PMID: 22719917 PMCID: PMC3376141 DOI: 10.1371/journal.pone.0038657] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 05/08/2012] [Indexed: 11/23/2022] Open
Abstract
Stem cell factor (SCF) is a growth factor, essential for haemopoiesis, mast cell development and melanogenesis. In the hematopoietic microenvironment (HM), SCF is produced either as a membrane-bound (-) or soluble (+) forms. Skin expression of SCF stimulates melanocyte migration, proliferation, differentiation, and survival. We report for the first time, a novel mRNA splice variant of SCF from the skin of white merino sheep via cloning and sequencing. Reverse transcriptase (RT)-PCR and molecular prediction revealed two different cDNA products of SCF. Full-length cDNA libraries were enriched by the method of rapid amplification of cDNA ends (RACE-PCR). Nucleotide sequencing and molecular prediction revealed that the primary 1519 base pair (bp) cDNA encodes a precursor protein of 274 amino acids (aa), commonly known as 'soluble' isoform. In contrast, the shorter (835 and/or 725 bp) cDNA was found to be a 'novel' mRNA splice variant. It contains an open reading frame (ORF) corresponding to a truncated protein of 181 aa (vs 245 aa) with an unique C-terminus lacking the primary proteolytic segment (28 aa) right after the D(175)G site which is necessary to produce 'soluble' form of SCF. This alternative splice (AS) variant was explained by the complete nucleotide sequencing of splice junction covering exon 5-intron (5)-exon 6 (948 bp) with a premature termination codon (PTC) whereby exons 6 to 9/10 are skipped (Cassette Exon, CE 6-9/10). We also demonstrated that the Northern blot analysis at transcript level is mediated via an intron-5 splicing event. Our data refine the structure of SCF gene; clarify the presence (+) and/or absence (-) of primary proteolytic-cleavage site specific SCF splice variants. This work provides a basis for understanding the functional role and regulation of SCF in hair follicle melanogenesis in sheep beyond what was known in mice, humans and other mammals.
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Affiliation(s)
| | - Dario Pediconi
- School of Environmental Sciences, University of Camerino, via Gentile III da Varano, Camerino (MC), Italy
| | - Carlo Renieri
- School of Environmental Sciences, University of Camerino, via Gentile III da Varano, Camerino (MC), Italy
| | - Antonietta La Terza
- School of Environmental Sciences, University of Camerino, via Gentile III da Varano, Camerino (MC), Italy
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Liu H, Leo C, Chen X, Wong BR, Williams LT, Lin H, He X. The mechanism of shared but distinct CSF-1R signaling by the non-homologous cytokines IL-34 and CSF-1. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:938-45. [PMID: 22579672 DOI: 10.1016/j.bbapap.2012.04.012] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 04/30/2012] [Indexed: 01/12/2023]
Abstract
Interleukin-34 (IL-34) and colony stimulating factor-1 (CSF-1) both signal through the CSF-1R receptor tyrosine kinase, but they have no sequence homology, and their functions and signaling activities are not identical. We report the crystal structures of mouse IL-34 alone and in complex with the N-terminal three immunoglobulin-like domains (D1-D3) of mouse CSF-1R. IL-34 is structurally related to other helical hematopoietic cytokines, but contains two additional helices integrally associated with the four shared helices. The non-covalently linked IL-34 homodimer recruits two copies of CSF-1R on the sides of the helical bundles, with an overall shape similar to the CSF-1:CSF-1R complex, but the flexible linker between CSF-1R D2 and D3 allows these domains to clamp IL-34 and CSF-1 at different angles. Functional dissection of the IL-34:CSF-1R interface indicates that the hydrophobic interactions, rather than the salt bridge network, dominate the biological activity of IL-34. To degenerately recognize two ligands with completely different surfaces, CSF-1R apparently takes advantage of different subsets of a chemically inert surface that can be tuned to fit different ligand shapes. Differentiated signaling between IL-34 and CSF-1 is likely achieved by the relative thermodynamic independence of IL-34 vs. negative cooperativity of CSF-1 at the receptor-recognition sites, in combination with the difference in hydrophobicity which dictates a more stable IL-34:CSF-1R complex compared to the CSF-1:CSF-1R complex.
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Affiliation(s)
- Heli Liu
- Department of Molecular Pharmacology & Biological Chemistry, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
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40
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Ma X, Lin WY, Chen Y, Stawicki S, Mukhyala K, Wu Y, Martin F, Bazan JF, Starovasnik MA. Structural basis for the dual recognition of helical cytokines IL-34 and CSF-1 by CSF-1R. Structure 2012; 20:676-87. [PMID: 22483114 DOI: 10.1016/j.str.2012.02.010] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 02/04/2012] [Accepted: 02/06/2012] [Indexed: 01/01/2023]
Abstract
Lacking any discernible sequence similarity, interleukin-34 (IL-34) and colony stimulating factor 1 (CSF-1) signal through a common receptor CSF-1R on cells of mononuclear phagocyte lineage. Here, the crystal structure of dimeric IL-34 reveals a helical cytokine fold homologous to CSF-1, and we further show that the complex architecture of IL-34 bound to the N-terminal immunoglobulin domains of CSF-1R is similar to the CSF-1/CSF-1R assembly. However, unique conformational adaptations in the receptor domain geometry and intermolecular interface explain the cross-reactivity of CSF-1R for two such distantly related ligands. The docking adaptations of the IL-34 and CSF-1 quaternary complexes, when compared to the stem cell factor assembly, draw a common evolutionary theme for transmembrane signaling. In addition, the structure of IL-34 engaged by a Fab fragment reveals the mechanism of a neutralizing antibody that can help deconvolute IL-34 from CSF-1 biology, with implications for therapeutic intervention in diseases with myeloid pathogenic mechanisms.
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MESH Headings
- Antibodies, Neutralizing/chemistry
- Baculoviridae
- Binding Sites
- Crystallography, X-Ray
- Humans
- Immunoglobulin Fab Fragments/chemistry
- Interleukins/antagonists & inhibitors
- Interleukins/chemistry
- Interleukins/genetics
- Kinetics
- Leukocytes, Mononuclear/cytology
- Leukocytes, Mononuclear/metabolism
- Macrophage Colony-Stimulating Factor/chemistry
- Macrophage Colony-Stimulating Factor/genetics
- Models, Molecular
- Protein Binding
- Protein Structure, Secondary
- Protein Structure, Tertiary
- Proto-Oncogene Proteins c-kit/chemistry
- Receptor, Macrophage Colony-Stimulating Factor/chemistry
- Receptor, Macrophage Colony-Stimulating Factor/genetics
- Recombinant Proteins/chemistry
- Recombinant Proteins/genetics
- Signal Transduction/genetics
- Stem Cell Factor/chemistry
- Structural Homology, Protein
- Thermodynamics
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Affiliation(s)
- Xiaolei Ma
- Department of Structural Biology, Genentech, Inc., 1 DNA Way, South San Francisco, CA 94080, USA
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41
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Elegheert J, Desfosses A, Shkumatov AV, Wu X, Bracke N, Verstraete K, Van Craenenbroeck K, Brooks BR, Svergun DI, Vergauwen B, Gutsche I, Savvides SN. Extracellular complexes of the hematopoietic human and mouse CSF-1 receptor are driven by common assembly principles. Structure 2011; 19:1762-72. [PMID: 22153499 PMCID: PMC3260422 DOI: 10.1016/j.str.2011.10.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 09/13/2011] [Accepted: 10/06/2011] [Indexed: 10/14/2022]
Abstract
The hematopoietic colony stimulating factor-1 receptor (CSF-1R or FMS) is essential for the cellular repertoire of the mammalian immune system. Here, we report a structural and mechanistic consensus for the assembly of human and mouse CSF-1:CSF-1R complexes. The EM structure of the complete extracellular assembly of the human CSF-1:CSF-1R complex reveals how receptor dimerization by CSF-1 invokes a ternary complex featuring extensive homotypic receptor contacts and striking structural plasticity at the extremities of the complex. Studies by small-angle X-ray scattering of unliganded hCSF-1R point to large domain rearrangements upon CSF-1 binding, and provide structural evidence for the relevance of receptor predimerization at the cell surface. Comparative structural and binding studies aiming to dissect the assembly principles of human and mouse CSF-1R complexes, including a quantification of the CSF-1/CSF-1R species cross-reactivity, show that bivalent cytokine binding to receptor coupled to ensuing receptor-receptor interactions are common denominators in extracellular complex formation.
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Affiliation(s)
- Jonathan Elegheert
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Ambroise Desfosses
- Unit for Virus Host-Cell Interactions, UMI 3265 UJF-EMBL-CNRS, 6 rue Jules Horowitz, BP 181 38042, Grenoble cedex 9, France
| | | | - Xiongwu Wu
- Laboratory of Computational Biology, National Heart Lung and Blood Institute, National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Nathalie Bracke
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Kenneth Verstraete
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Kathleen Van Craenenbroeck
- Laboratory of Eukaryotic Gene Expression and Signal Transduction (LEGEST), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Bernard R. Brooks
- Laboratory of Computational Biology, National Heart Lung and Blood Institute, National Institutes of Health (NIH), Bethesda, MD 20892, USA
| | - Dmitri I. Svergun
- Biological Small Angle Scattering Group, EMBL, Notkestraβe 85, 22603 Hamburg, Germany
| | - Bjorn Vergauwen
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Irina Gutsche
- Unit for Virus Host-Cell Interactions, UMI 3265 UJF-EMBL-CNRS, 6 rue Jules Horowitz, BP 181 38042, Grenoble cedex 9, France
| | - Savvas N. Savvides
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
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Tarasova A, Haylock D, Winkler D. Principal signalling complexes in haematopoiesis: Structural aspects and mimetic discovery. Cytokine Growth Factor Rev 2011; 22:231-53. [DOI: 10.1016/j.cytogfr.2011.09.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 09/06/2011] [Indexed: 11/17/2022]
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43
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Arock M, Valent P. Pathogenesis, classification and treatment of mastocytosis: state of the art in 2010 and future perspectives. Expert Rev Hematol 2011; 3:497-516. [PMID: 21083038 DOI: 10.1586/ehm.10.42] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Mastocytosis is a myeloid neoplasm characterized by abnormal accumulation and frequent activation of mast cells (MCs) in various organs. Organ systems typically involved are the bone marrow, skin, liver and gastrointestinal tract. In most adult patients, the systemic form of mastocytosis (SM) is diagnosed, which includes an indolent subvariant, an aggressive subvariant and a leukemic subvariant, also termed MC leukemia. Whereas in pediatric mastocytosis, which is usually confined to the skin, a number of different KIT mutations and other defects may be detected, the KIT mutation D816V is detectable in most (adult) patients with SM. In a subset of these patients, additional oncogenic factors may lead to enhanced survival and growth of MCs and, thus, to advanced SM. Other factors may lead to MC activation, with consecutive anaphylactic reactions that can be severe or even fatal. Treatment of SM usually focuses on symptom relief by histamine receptor antagonists and other supportive therapy. However, in aggressive and leukemic variants, cytoreductive and targeted drugs must be applied. Unfortunately, the prognosis in these patients remains poor, even when treated with novel KIT-targeting agents, polychemotherapy or stem cell transplantation. This article provides a summary of our knowledge on the pathogenesis and on treatment options in SM.
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Affiliation(s)
- Michel Arock
- Laboratoire de Biologie et Pharmacologie Appliquée, CNRS UMR 8113, Ecole Normale Supérieure de Cachan, 61, Ave du Président Wilson, 94235 Cachan Cedex, France.
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44
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Characterization of an alternative splicing by a NAGNAG splice acceptor site in the porcine KIT gene. Genes Genomics 2011. [DOI: 10.1007/s13258-010-0156-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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45
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Gounder MM, Maki RG. Molecular basis for primary and secondary tyrosine kinase inhibitor resistance in gastrointestinal stromal tumor. Cancer Chemother Pharmacol 2011; 67 Suppl 1:S25-43. [PMID: 21116624 PMCID: PMC3275340 DOI: 10.1007/s00280-010-1526-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Accepted: 11/10/2010] [Indexed: 02/08/2023]
Abstract
Small molecule kinase inhibitors have irrevocably altered cancer treatment. March 2010 marks the 10th anniversary of using imatinib in gastrointestinal stromal tumors (GIST), a cardinal example of the utility of such targeted therapy in a solid tumor. Before imatinib, metastatic GIST was frustrating to treat due to its resistance to standard cytotoxic chemotherapy. Median survival for patients with metastatic GIST improved from 19 to 60 months with imatinib. In treating patients with GIST, two patterns of tyrosine kinase inhibitor resistance have been observed. In the first, ~9-14% of patients have progression within 3 months of starting imatinib. These patients are classified as having primary or early resistance. Median progression-free survival (PFS) on imatinib is approximately 24 months; patients with later progression are classified as having secondary or acquired resistance. Primary studies and a meta-analysis of studies of imatinib in GIST patients have identified prognostic features that contribute to treatment failure. One of the strongest predictors for success of therapy is KIT or PDGFRA mutational status. Patients with KIT exon 11 mutant GIST have better response rates, PFS, and overall survival compared to other mutations. A great deal has been learned in the last decade about sensitivity and resistance of GIST to imatinib; however, many unanswered questions remain about secondary resistance mechanisms and clinical management in the third- and fourth-line setting. This review will discuss the role of dose effects, and early and late resistance to imatinib and their clinical implications. Patients intolerant to imatinib (5%) and those who progress on imatinib are treated with sunitinib. The mechanism of resistance to sunitinib is unknown at this time but is also appears related to growth of clones with secondary mutations in KIT. Third- and fourth-line treatments of GIST and with future treatment strategies are also discussed.
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Affiliation(s)
| | - Robert G. Maki
- Memorial Sloan-Kettering Cancer Center, New York, NY, USA
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46
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I787 provides signals for c-Kit receptor internalization and functionality that control mast cell survival and development. Blood 2010; 116:2665-75. [PMID: 20595514 DOI: 10.1182/blood-2009-06-228460] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mast cell (MC) differentiation, survival, and activation are controlled by the membrane tyrosine kinase c-Kit upon interaction with stem cell factor (SCF). Here we describe a single point mutation induced by N-ethyl-N-nitrosurea (ENU) mutagenesis in C57BL/6J mice-an A to T transversion at position 2388 (exon 17) of the c-Kit gene, resulting in the isoleucine 787 substitution by phenylalanine (787F), and analyze the consequences of this mutation for ligand binding, signaling, and MC development. The Kit(787F/787F) mice carrying the single amino acid exchange of c-Kit lacks both mucosal and connective tissue-type MCs. In bone marrow-derived mast cells (BMMCs), the 787F mutation does not affect SCF binding and c-Kit receptor shedding, but strongly impairs SCF-induced cytokine production, degranulation enhancement, and apoptosis rescue. Interestingly, c-Kit downstream signaling in 787F BMMCs is normally initiated (Erk1/2 and p38 activation as well as c-Kit autophosphorylation) but fails to be sustained thereafter. In addition, 787F c-Kit does not efficiently mediate Cbl activation, leading to the absence of subsequent receptor ubiquitination and impaired c-Kit internalization. Thus, I787 provides nonredundant signals for c-Kit internalization and functionality.
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47
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Yao K, Ge W. Kit System in the Zebrafish Ovary: Evidence for Functional Divergence of Two Isoforms of Kit (Kita and Kitb) and Kit Ligand (Kitlga and Kitlgb) During Folliculogenesis1. Biol Reprod 2010; 82:1216-26. [DOI: 10.1095/biolreprod.109.082644] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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48
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Dey S, Pal A, Chakrabarti P, Janin J. The subunit interfaces of weakly associated homodimeric proteins. J Mol Biol 2010; 398:146-60. [PMID: 20156457 DOI: 10.1016/j.jmb.2010.02.020] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 02/10/2010] [Accepted: 02/10/2010] [Indexed: 02/07/2023]
Abstract
We analyzed subunit interfaces in 315 homodimers with an X-ray structure in the Protein Data Bank, validated by checking the literature for data that indicate that the proteins are dimeric in solution and that, in the case of the "weak" dimers, the homodimer is in equilibrium with the monomer. The interfaces of the 42 weak dimers, which are smaller by a factor of 2.4 on average than in the remainder of the set, are comparable in size with antibody-antigen or protease-inhibitor interfaces. Nevertheless, they are more hydrophobic than in the average transient protein-protein complex and similar in amino acid composition to the other homodimer interfaces. The mean numbers of interface hydrogen bonds and hydration water molecules per unit area are also similar in homodimers and transient complexes. Parameters related to the atomic packing suggest that many of the weak dimer interfaces are loosely packed, and we suggest that this contributes to their low stability. To evaluate the evolutionary selection pressure on interface residues, we calculated the Shannon entropy of homologous amino acid sequences at 60% sequence identity. In 93% of the homodimers, the interface residues are better conserved than the residues on the protein surface. The weak dimers display the same high degree of interface conservation as other homodimers, but their homologs may be heterodimers as well as homodimers. Their interfaces may be good models in terms of their size, composition, and evolutionary conservation for the labile subunit contacts that allow protein assemblies to share and exchange components, allosteric proteins to undergo quaternary structure transitions, and molecular machines to operate in the cell.
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Affiliation(s)
- Sucharita Dey
- Bioinformatics Centre, Bose Institute, P-1/12 CIT Scheme VIIM, Calcutta 700 054, India
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49
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Jagarlamudi K, Reddy P, Adhikari D, Liu K. Genetically modified mouse models for premature ovarian failure (POF). Mol Cell Endocrinol 2010; 315:1-10. [PMID: 19643165 DOI: 10.1016/j.mce.2009.07.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Revised: 06/18/2009] [Accepted: 07/03/2009] [Indexed: 11/16/2022]
Abstract
Premature ovarian failure (POF) is a complex disorder that affects approximately 1% of women. POF is characterized by the depletion of functional ovarian follicles before the age of 40 years, and clinically, patients may present with primary amenorrhea or secondary amenorrhea. Although some genes have been hypothesized to be candidates responsible for POF, the etiology of most of the cases is idiopathic, with the underlying causes still unidentified because of the heterogeneity of the disease. In this review, we consider some mutant mouse models that exhibit phenotypes which are comparable to human POF, and we suggest that the use of these mouse models may help us to gain a better understanding of the molecular mechanisms underlying POF in humans.
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Affiliation(s)
- Krishna Jagarlamudi
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-901 87 Umeå, Sweden.
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50
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Katzenback BA, Belosevic M. Molecular and functional characterization of kita and kitla of the goldfish (Carassius auratus L.). DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2009; 33:1165-1175. [PMID: 19527751 DOI: 10.1016/j.dci.2009.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 06/05/2009] [Accepted: 06/06/2009] [Indexed: 05/27/2023]
Abstract
Kit ligand and its type III tyrosine kinase receptor Kit promotes the survival, proliferation and differentiation of progenitor cells involved in mammalian myelopoiesis. In this study we report on the molecular and functional characterization of kit receptor A (kita) and kit ligand A (kitla) from the goldfish. Both kita and kitla were ubiquitously expressed in goldfish tissues, with higher mRNA levels observed in the kidney and spleen, the major hematopoietic organs of fish. Furthermore, both kita and kitla expressions decreased in a time-dependent manner in goldfish primary kidney macrophage (PKM) cultures, as progenitor to macrophage development progressed, and the highest expressions of both the receptor and ligand were observed in sorted progenitor cell populations. Activation of mature macrophage cultures increased both kita and kitla expressions. Kit ligand A induced chemotactic response, proliferation and survival of PKM cells in a dose-dependent manner, but did not induce differentiation of early PKM cells. These results are consistent with the role of kita and kitla during myelopoiesis of higher vertebrates and suggest a conserved mechanism of macrophage development throughout vertebrates.
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Affiliation(s)
- Barbara A Katzenback
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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