Identification of the effector domain of biglycan that facilitates BMP-2 osteogenic function
Bone Morphogenetic Protein 2
Protein Interaction Domains and Motifs
Recombinant Fusion Proteins
Spectroscopy, Fourier Transform Infrared
Permanent link to this recordhttp://hdl.handle.net/20.500.12613/4670
MetadataShow full item record
Abstract© 2018 The Author(s). We have reported that recombinant biglycan (BGN) core protein accelerates bone formation in vivo by enhancing bone morphogenetic protein (BMP)-2 function. The purpose of the present study was to identify the specific domain ("effector") within the BGN core protein that facilitates BMP-2 osteogenic function. Thus, we generated various recombinant and synthetic peptides corresponding to several domains of BGN, and tested their effects on BMP-2 functions in vitro. The results demonstrated that the leucine-rich repeats 2-3 domain (LRR2-3) of BGN significantly enhanced the BMP-2 induced Smad1/5/9 phosphorylation, osteogenic gene expression, and alkaline phosphatase activity in myogenic C2C12 cells. Furthermore, addition of LRR2-3 to osteoblastic MC3T3-E1 cells accelerated in vitro mineralization without compromising the quality of the mineral and matrix. These data indicate that LRR2-3 is, at least in part, responsible for BGN's ability to enhance BMP-2 osteogenic function, and it could be useful for bone tissue regeneration.
Citation to related workSpringer Science and Business Media LLC
Has partScientific Reports
ADA complianceFor Americans with Disabilities Act (ADA) accommodation, including help with reading this content, please contact firstname.lastname@example.org
Showing items related by title, author, creator and subject.
A Spiroligomer α-Helix Mimic That Binds HDM2, Penetrates Human Cells and Stabilizes HDM2 in Cell CultureBrown, ZZ; Akula, K; Arzumanyan, A; Alleva, J; Jackson, M; Bichenkov, E; Sheffield, JB; Feitelson, MA; Schafmeister, CE (2012-10-18)We demonstrate functionalized spiroligomers that mimic the HDM2-bound conformation of the p53 activation domain. Spiroligomers are stereochemically defined, functionalized, spirocyclic monomers coupled through pairs of amide bonds to create spiro-ladder oligomers . Two series of spiroligomers were synthesized, one of structural analogs and one of stereochemical analogs, from which we identified compound 1, that binds HDM2 with a Kd value of 400 nM. The spiroligomer 1 penetrates human liver cancer cells through passive diffusion and in a dose-dependent and time-dependent manner increases the levels of HDM2 more than 30-fold in Huh7 cells in which the p53/HDM2 negative feed-back loop is inoperative. This is a biological effect that is not seen with the HDM2 ligand nutlin-3a. We propose that compound 1 modulates the levels of HDM2 by stabilizing it to proteolysis, allowing it to accumulate in the absence of a p53/HDM2 feedback loop. © 2012 Brown et al.
The retinoblastoma family: Twins or distant cousins?Claudio, PP; Tonini, T; Giordano, A; Giordano, Antonio|0000-0002-5959-016X (2002-09-23)The destiny of a cell - whether it undergoes division, differentiation or death - results from an intricate balance of many regulators, including oncoproteins, tumor-suppressor proteins and cell-cycle-associated proteins. One of the better-studied tumor suppressors is the retinoblastoma protein, known as pRb or p105. Two recently identified proteins, pRb2/p130 and p107, show structural and functional similarities to pRb, and these proteins and their orthologs make up the retinoblastoma (Rb) family. Members of the family have been found in animals and plants, and a related protein is known in the alga Chlamydomonas. Members of the Rb family are bound and inactivated by viral proteins and, in turn, bind cellular transcription factors and repress their function, and can also form complexes with cyclins and cyclin-dependent kinases and with histone deacetylases. The are found in the nucleus and their subnuclear localization depends on binding to the nuclear matrix. Members of the family form part of a signal-transduction pathway called the Rb pathway, which is important in cell-cycle regulation and have roles in growth suppression, differentiation and apoptosis in different organisms and cell types.
Perturbation of synapsins homeostasis through HIV-1 Tat-mediated suppression of BAG3 in primary neuronal cellsMohseni Ahooyi, T; Torkzaban, B; Shekarabi, M; Tahrir, FG; Decoppet, EA; Cotto, B; Langford, D; Amini, S; Khalili, K (2019-07-01)© 2019, The Author(s). HIV-1 Tat is known to be released by HIV infected non-neuronal cells in the brain, and after entering neurons, compromises brain homeostasis by impairing pro-survival pathways, thus contributing to the development of HIV-associated CNS disorders commonly observed in individuals living with HIV. Here, we demonstrate that synapsins, phosphoproteins that are predominantly expressed in neuronal cells and play a vital role in modulating neurotransmitter release at the pre-synaptic terminal, and neuronal differentiation become targets for Tat through autophagy and protein quality control pathways. We demonstrate that the presence of Tat in neurons results in downregulation of BAG3, a co-chaperone for heat shock proteins (Hsp70/Hsc70) that is implicated in protein quality control (PQC) processes by eliminating mis-folded and damaged proteins, and selective macroautophagy. Our results show that treatment of cells with Tat or suppression of BAG3 expression by siRNA in neuronal cells disturbs subcellular distribution of synapsins and synaptotagmin 1 (Syt1) leading to their accumulation in the neuronal soma and along axons in a punctate pattern, rather than being properly distributed at axon-terminals. Further, our results revealed that synapsins partially lost their stability and their removal via lysosomal autophagy was noticeably impaired in cells with low levels of BAG3. The observed impairment of lysosomal autophagy, under this condition, is likely caused by cells losing their ability to process LC3-I to LC3-II, in part due to a decrease in the ATG5 levels upon BAG3 knockdown. These observations ascribe a new function for BAG3 in controlling synaptic communications and illuminate a new downstream target for Tat to elicit its pathogenic effect in impacting neuronal cell function and behavior.