Dataset Information

Disentangling mechanisms involved in collagen pyridinoline cross-linking: The immunophilin FKBP65 is critical for dimerization of lysyl hydroxylase 2.

ABSTRACT: Collagens are subjected to extensive posttranslational modifications, such as lysine hydroxylation. Bruck syndrome (BS) is a connective tissue disorder characterized at the molecular level by a loss of telopeptide lysine hydroxylation, resulting in reduced collagen pyridinoline cross-linking. BS results from mutations in the genes coding for lysyl hydroxylase (LH) 2 or peptidyl-prolyl cis-trans isomerase (PPIase) FKBP65. Given that the immunophilin FKBP65 does not exhibit LH activity, it is likely that LH2 activity is somehow dependent on FKPB65. In this report, we provide insights regarding the interplay between LH2 and FKBP65. We found that FKBP65 forms complexes with LH2 splice variants LH2A and LH2B but not with LH1 and LH3. Ablating the catalytic activity of FKBP65 or LH2 did not affect complex formation. Both depletion of FKBP65 and inhibition of FKBP65 PPIase activity reduced the dimeric (active) form of LH2 but did not affect the binding of monomeric (inactive) LH2 to procollagen I?1. Furthermore, we show that LH2A and LH2B cannot form heterodimers with each other but are able to form heterodimers with LH1 and LH3. Collectively, our results indicate that FKBP65 is linked to pyridinoline cross-linking by specifically mediating the dimerization of LH2. Moreover, FKBP65 does not interact with LH1 and LH3, explaining why in BS triple-helical hydroxylysines are not affected. Our results provide a mechanistic link between FKBP65 and the loss of pyridinolines and may hold the key to future treatments for diseases related to collagen cross-linking anomalies, such as fibrosis and cancer.

SUBMITTER: Gjaltema RA

PROVIDER: S-EPMC4932945 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Disentangling mechanisms involved in collagen pyridinoline cross-linking: The immunophilin FKBP65 is critical for dimerization of lysyl hydroxylase 2.

Gjaltema Rutger A F RA van der Stoel Miesje M MM Boersema Miriam M Bank Ruud A RA

Proceedings of the National Academy of Sciences of the United States of America 20160613 26

Collagens are subjected to extensive posttranslational modifications, such as lysine hydroxylation. Bruck syndrome (BS) is a connective tissue disorder characterized at the molecular level by a loss of telopeptide lysine hydroxylation, resulting in reduced collagen pyridinoline cross-linking. BS results from mutations in the genes coding for lysyl hydroxylase (LH) 2 or peptidyl-prolyl cis-trans isomerase (PPIase) FKBP65. Given that the immunophilin FKBP65 does not exhibit LH activity, it is like ...[more]

PMID: 27298363

Similar Datasets

Project description:The inability to recapitulate native tissue biomechanics, especially tensile properties, hinders progress in regenerative medicine. To address this problem, strategies have focused on enhancing collagen production. However, manipulating collagen cross-links, ubiquitous throughout all tissues and conferring mechanical integrity, has been underinvestigated. A series of studies examined the effects of lysyl oxidase (LOX), the enzyme responsible for the formation of collagen cross-links. Hypoxia-induced endogenous LOX was applied in multiple musculoskeletal tissues (i.e., cartilage, meniscus, tendons, ligaments). Results of these studies showed that both native and engineered tissues are enhanced by invoking a mechanism of hypoxia-induced pyridinoline (PYR) cross-links via intermediaries like LOX. Hypoxia was shown to enhance PYR cross-linking 1.4- to 6.4-fold and, concomitantly, to increase the tensile properties of collagen-rich tissues 1.3- to 2.2-fold. Direct administration of exogenous LOX was applied in native cartilage and neocartilage generated using a scaffold-free, self-assembling process of primary chondrocytes. Exogenous LOX was found to enhance native tissue tensile properties 1.9-fold. LOX concentration- and time-dependent increases in PYR content (∼ 16-fold compared with controls) and tensile properties (approximately fivefold compared with controls) of neocartilage were also detected, resulting in properties on par with native tissue. Finally, in vivo subcutaneous implantation of LOX-treated neocartilage in nude mice promoted further maturation of the neotissue, enhancing tensile and PYR content approximately threefold and 14-fold, respectively, compared with in vitro controls. Collectively, these results provide the first report, to our knowledge, of endogenous (hypoxia-induced) and exogenous LOX applications for promoting collagen cross-linking and improving the tensile properties of a spectrum of native and engineered tissues both in vitro and in vivo.

Project description:Antibodies to pure lysyl hydroxylase from whole chick embryos were prepared in rabbits and used for immunological characterization of this enzyme of collagen biosynthesis. In double immunodiffusion a single precipitation line was seen between the antiserum and crude or pure chick-embryo lysyl hydroxylase. The antiserum effectively inhibited chick-embryo lysyl hydroxylase activity, whether measured with the biologically prepared protocollagen substrate or a synthetic peptide consisting of only 12 amino acids. This suggests that the antigenic determinant was located near the active site of the enzyme molecule. Essentially identical amounts of the antiserum were required for 40% inhibition of the same amount of lysyl hydroxylase activity units from different chick-embryo tissues synthesizing various genetically distinct collagen types. In double immunodiffusion a single precipitation line of complete identity was found between the antiserum and the purified enzyme from whole chick embryos and the crude enzymes from chick-embryo tendon, cartilage and kidneys. These results do not support the hypothesis that lysyl hydroxylase has collagen-type-specific or tissue-specific isoenzymes with markedly different specific activities or immunological properties. The antibodies to chick-embryo lysyl hydroxylase showed a considerable degree of species specificity when examined either by activity-inhibition assay or by double immuno-diffusion. Nevertheless, a distinct, although weak, cross-reactivity was found between the chick-embryo enzyme and those from all mammalian tissues tested. The antiserum showed no cross-reactivity against prolyl 3-hydroxylase, hydroxylysyl galactosyl-transferase or galactosylhydroxylysyl glucosyltransferase in activity-inhibition assays, whereas a distinct cross-reactivity was found against prolyl 4-hydroxylase. Furthermore, antiserum to pure prolyl 4-hydroxylase inhibited lysyl hydroxylase activity. These findings suggest that there are structural similarities between these two enzymes, possibly close to or at their active sites.

Dataset Information

Disentangling mechanisms involved in collagen pyridinoline cross-linking: The immunophilin FKBP65 is critical for dimerization of lysyl hydroxylase 2.

Publications

Disentangling mechanisms involved in collagen pyridinoline cross-linking: The immunophilin FKBP65 is critical for dimerization of lysyl hydroxylase 2.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure