2 å crystal structure of an extracellular fragment of human CD40 ligand

Karpusas, Michael; Hsu, Yen-Ming; Wang, Jia-Huai; Thompson, Jeffrey P.; Lederman, Seth; Chess, Leonard; Thomas, David W.

doi:10.1016/s0969-2126(01)00239-8

Cited by 225 publications

(153 citation statements)

References 37 publications

(42 reference statements)

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“…It has been reported that the receptors and the ligands form a trimeric structure (Karpusas et al, 1995;Gruss, 1996;Schneider et al, 1997;Hymowitz et al, 1999). Interestingly the ligands are expressed as transmembrane proteins but soluble forms have been identified for all of them (Schneider and Tschopp, 2000).…”

Section: Death Receptor Proteinsmentioning

confidence: 99%

Synthetic retinoids as inducers of apoptosis in ovarian carcinoma cell lines

Holmes¹,

Soprano²,

Soprano³

2004

Journal Cellular Physiology

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Apoptosis is also known as programmed cell death. Apoptosis plays an essential role in maintaining normal tissue and cell physiology in multicellular organisms. Clearance of aberrant or pre-cancerous cells occurs through the induction of apoptosis. It has been reported that many tumors and tumor cell lines have dysfunctional apoptosis signaling, causing these tumors to escape immune monitoring and internal cellular control mechanisms. One potential cause of this dysfunctional apoptosis is the tumor suppressor p53, an important regulator of growth arrest and apoptosis that is mutated in over 50% of all cancers. Retinoids have great potential in the areas of cancer therapy and chemoprevention. While some tumor cells are sensitive to the growth inhibitory effects of natural retinoids such as all-trans-retinoic acid (ATRA), many ovarian tumor cells are not. 6-[3-(1-Admantyl)]-4-hydroxyphenyl]-2-naphthalene carboxylic acid (CD437) and fenretinide N-[4-hydroxyphenyl] retinamide (4-HPR) are conformationally restricted synthetic retinoids that induce growth arrest and apoptosis in both ATRA-sensitive and ATRA-resistant ovarian tumor cell lines. Recently, we have identified the molecular pathways of apoptosis induced by treatment of ovarian carcinoma cells with mutated p53 by CD437 and 4-HPR.

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Section: Death Receptor Proteinsmentioning

confidence: 99%

Synthetic retinoids as inducers of apoptosis in ovarian carcinoma cell lines

Holmes¹,

Soprano²,

Soprano³

2004

Journal Cellular Physiology

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“…In the CD40L.G 4 S.A vector, CD40L is linked to the 4070A-SU via a non-cleavable AAAG 4 S linker, and in CD40L.MMP.A, via a MMP-cleavable linker (AAAPLGLWA). The SfiI-NotI PCR fragment encoding the 146 amino acids of the soluble extracellular domain of the trimeric CD40L (Gly 116-Leu 261) 30 was generated using a CD40L cDNA template (ATCC 79813; Rockland, MD, USA) and two primers (with restriction sites underlined), sCD40Lb (5Ј Ͼ CCG GTA CCG GCC CAG CCG GCC GGT GAT CAG AAT CCT CAA ATT GC) with a SfiI site and nCD40Lf (5Ј Ͼ AAG TCT TAG CGG CCG CGA GTT TGA GTA AGC CAA AGG) with a NotI site. To obtain CD40L.G 4 S.A and CD40L.MMP.A, the SfiI-NotI digested CD40L PCR fragment was cloned into SfiI-NotI digested E.G 4 S.A or E.MMP.A backbones, respectively.…”

Section: Construction Of Chimeric Envelope Expression Vectorsmentioning

confidence: 99%

Selective transduction of protease-rich tumors by matrix-metalloproteinase-targeted retroviral vectors

et al. 1999

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We recently showed that retroviral vectors can be targeted matrix-metalloproteinase (MMP)-activatable vectors, we through protease substrate interactions. Infectivity is demonstrated highly efficient and selective transduction of blocked by a polypeptide fused to the viral envelope glyco-MMP-rich target cells in a heterogeneous cell population. protein (SU) and is restored when a protease cleaves the In vivo, the MMP-targeted vectors showed strong selecconnecting linker, releasing the inhibitory polypeptide from tivity for MMP-rich tumor xenografts. Protease-activatable the viral surface. Protease specificity is achieved by enginvectors offer new possibilities for in vivo targeting of eering the sequence of the linker. Here, using two different gene delivery.

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“…We have generated a three-dimensional structure of CD40L and CD40 using the X-ray structure of the receptor binding extracellular portion of CD40L (Karpusas et al, 1995), together with a model of CD40 based upon the modular approach of Naismith and Sprang (1998; hence called Model 2). Model 2 was used to identify interaction sites between the receptor and ligand, several of which were subsequently tested using site-directed mutagenesis.…”

Section: Cdqo 41 59mentioning

confidence: 99%

“…The sequence alignment used to generate Model 2 is shown in Figure 3. As with previously published models (Bajorath et al, 1995a(Bajorath et al, , 1995bBajorath & Aruffo, 1997), we based the structural alignment of CD40 on CD40L on the crystal structure of TNF Receptor with TNF-p. Our assumption is that the high degree of structural similarity between CD40L and TNF-P (Karpusas et al, 1995) extends to the way that their receptors are structurally aligned. To align CD40L with CD40, our first step was to align the crystal structure of CD40L with the TNF-P/TNFR structure, using the strands A-H of TNF-J as structural equivalences (Karpusas et al, 1995).…”

Section: Cd4ol and Cd40 Structurementioning

confidence: 99%

The role of polar interactions in the molecular recognition of CD40L with its receptor CD40

et al. 1998

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CD40 Ligand (CD40L) is transiently expressed on the surface of T-cells and binds to CD40, which is expressed on the surface of B-cells. This binding event leads to the differentiation, proliferation, and isotype switching of the B-cells. The physiological importance of CD40L has been demonstrated by the fact that expression of defective CD40L protein causes an immunodeficiency state characterized by high IgM and low IgG serum levels, indicating faulty T-cell dependent B-cell activation. To understand the structural basis for CD40L/CD40 association, we have used a combination of molecular modeling, mutagenesis, and X-ray crystallography. The structure of the extracellular region of CD4OL was determined by protein crystallography, while the CD40 receptor was built using homology modeling based upon a novel alignment of the TNF receptor superfamily, and using the X-ray structure of the TNF receptor as a template. The model shows that the interface of the complex is composed of charged residues, with CD4OL presenting basic side chains (K143, R203, R207), and CD40 presenting acidic side chains (D84, El 14, E l 17). These residues were studied experimentally through site-directed mutagenesis, and also theoretically using electrostatic calculations with the program Delphi. The mutagenesis data explored the role of the charged residues in both CD40L and CD40 by switching to Ala (K143A, R203A, R207A of CD40L, and E74A, D84A, El14A, E l 17A of CD40), charge reversal (K143E, R203E, R207E of CD40L, and D84R, E l 14R, El 17R of CD40), mutation to a polar residue (K143N, R207N, R207Q of C340L, and D84N, E l 17N of CD40), and for the basic side chains in CD40L, isosteric substitution to a hydrophobic side chain (R203M, R207M). All the charge-reversal mutants and the majority of the Met and Ala substitutions led to loss of binding, suggesting that charged interactions stabilize the complex. This was supported by the Delphi calculations which confirmed that the CD40/CD40L residue pairs E74-R203, D84-R207, and El 17-R207 had a net stabilizing effect on the complex. However, the substitution of hydrophilic side chains at several of the positions was tolerated, which suggests that although charged interactions stabilize the complex, charge per se is not crucial at all positions. Finally, we compared the electrostatic surface of TNFjTNFR with CD40L/CD40 and have identified a set of polar interactions surrounded by a wall of hydrophobic residues that appear to be similar but inverted between the two complexes.

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2 å crystal structure of an extracellular fragment of human CD40 ligand

Cited by 225 publications

References 37 publications

Synthetic retinoids as inducers of apoptosis in ovarian carcinoma cell lines

Synthetic retinoids as inducers of apoptosis in ovarian carcinoma cell lines

Selective transduction of protease-rich tumors by matrix-metalloproteinase-targeted retroviral vectors

The role of polar interactions in the molecular recognition of CD40L with its receptor CD40

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