Molecular Characterization of an Ependymin Precursor from Goldfish Brain

Königstorfer, Andreas; Sterrer, S.; Eckerskorn, Christoph; Lottspeich, Friedrich; Schmidt, Rupert; Hoffmann, Werner

doi:10.1111/j.1471-4159.1989.tb10932.x

Cited by 29 publications

(8 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Several N-glycosylation variants of ependymin have been identified, and an important role appears to be the binding of calcium via N-linked sialic acid residues (Konigstorfer et al, 1989;Ganss and Hoffmann, 1993;Hoffman, 1994). Calcium binding activates functionally significant conformational transitions of the ependymin glycoproteins, and it has been suggested that ependymin plays an important role in calcium homeostasis in the brain (Shashoua, 1991).…”

Section: Introductionmentioning

confidence: 97%

Identification and Characterization of a Novel Family of Mammalian Ependymin-Related Proteins (MERPs) in Hematopoietic, Nonhematopoietic, and Malignant Tissues

Apostolopoulos

McLeod

Collier

et al. 2001

DNA and Cell Biology

View full text Add to dashboard Cite

Evidence is presented for a family of mammalian homologs of ependymin, which we have termed the mammalian ependymin-related proteins (MERPs). Ependymins are secreted glycoproteins that form the major component of the cerebrospinal fluid in many teleost fish. We have cloned the entire coding region of human MERP-1 and mapped the gene to chromosome 7p14.1 by fluorescence in situ hybridization. In addition, three human MERP pseudogenes were identified on chromosomes 8, 16, and X. We have also cloned the mouse MERP-1 homolog and an additional family member, mouse MERP-2. Then, using bioinformatics, the mouse MERP-2 gene was localized to chromosome 13, and we identified the monkey MERP-1 homolog and frog ependymin-related protein (ERP). Despite relatively low amino acid sequence conservation between piscine ependymins, toad ERP, and MERPs, several amino acids (including four key cysteine residues) are strictly conserved, and the hydropathy profiles are remarkably alike, suggesting the possibilities of similar protein conformation and function. As with fish ependymins, frog ERP and MERPs contain a signal peptide typical of secreted proteins. The MERPs were found to be expressed at high levels in several hematopoietic cell lines and in nonhematopoietic tissues such as brain, heart, and skeletal muscle, as well as several malignant tissues and malignant cell lines. These findings suggest that MERPs have several potential roles in a range of cells and tissues.

show abstract

Section: Introductionmentioning

confidence: 97%

Identification and Characterization of a Novel Family of Mammalian Ependymin-Related Proteins (MERPs) in Hematopoietic, Nonhematopoietic, and Malignant Tissues

Apostolopoulos

McLeod

Collier

et al. 2001

DNA and Cell Biology

View full text Add to dashboard Cite

show abstract

“…EPN is secreted by meningeal cells [13]. It has two glycoforms (37 kDa and 32 kDa) and is an important glycoprotein in the cerebrospinal £uid of teleost ¢sh [14]. A bound form of EPN has been identi¢ed in the extracellular matrix of the cerebral blood vessels.…”

Section: Introductionmentioning

confidence: 99%

Cold‐induced ependymin expression in zebrafish and carp brain: implications for cold acclimation

Tang

Sun²,

Sun

et al. 1999

FEBS Letters

View full text Add to dashboard Cite

Cold acclimation has been suggested to be mediated by alternations in the gene expression pattern in the cold-adapted fish. To investigate the mechanism of cold acclimation in fish brain at the molecular level, relevant subsets of differentially expressed genes of interest were identified and cloned by the PCR-based subtraction suppression hybridization. Characterization of the selected cold-induced cDNA clones revealed one encoding ependymin. This gene was shown to be brain-specific. The expression of ependymin was induced by a temperature shift from 25³C to 6³C in Cyprinus carpio or 12³C in Danio rerio. Activation of ependymin was detected 2 h after cold exposure and peaked at more than 10-fold at 12 h. This peak level remains unchanged until the temperature returns to 25³C. Although the amount of soluble ependymin protein in brain was not changed by cold treatment, its level in the fibrous insoluble polymers increased 2-fold after exposure to low temperature. These findings indicate that the increase in ependymin expression is an early event that may play an important role in the cold acclimation of fish.z 1999 Federation of European Biochemical Societies.

show abstract

“…A study on the polymerization of ependymins led also to a speculation on the function of ependymins for neural plasticity (Shashoua, 1991). From the first molecular characterization of goldfish ependymins it was tempting to speculate that negatively charged clusters may act as Ca''-binding sites (Konigstorfer et al, 1989a), because no other consensus motifs were detectable. Remarkably, these clusters are not strictly conserved in ependymins from various orders of teleost fish (Miiller-Schmid et al, 1992.…”

mentioning

confidence: 99%

Calcium binding to sialic acids and its effect on the conformation of ependymins

Ganß

Hoffmann

1993

European Journal of Biochemistry

View full text Add to dashboard Cite

Soluble ependymins form the predominant protein constituents in the cerebrospinal fluid from many orders of teleost fish. Furthermore, these glycoproteins also exist in a bound form associated with the extracellular matrix. Ependymins are synthesized in meningeal fibroblasts. In goldfish, their synthesis is increased during the regeneration of the optic nerve and they share several characteristics with molecules involved in cell contact phenomena. In this study, we show by a calcium overlay technique that ependymins from goldfish and rainbow trout are able to bind 45Ca2+. However, nearly all of this Ca2+‐binding capacity is lost after digestion with sialidase. Furthermore, circular‐dichroism spectra from FPLC‐purified rainbow trout ependymins have been recorded in the presence and absence of Ca2+. Below 250 nm, the CD spectrum showed a characteristic minimum of ellipticity at 217 nm typical of β structures. This signal is independent of the Ca2+ concentration. In contrast, the complex signal at 250–310 nm mainly decreased with increasing Ca2+ concentration indicating changes in the environment of aromatic side chains.

show abstract

Molecular Characterization of an Ependymin Precursor from Goldfish Brain

Cited by 29 publications

References 17 publications

Identification and Characterization of a Novel Family of Mammalian Ependymin-Related Proteins (MERPs) in Hematopoietic, Nonhematopoietic, and Malignant Tissues

Identification and Characterization of a Novel Family of Mammalian Ependymin-Related Proteins (MERPs) in Hematopoietic, Nonhematopoietic, and Malignant Tissues

Cold‐induced ependymin expression in zebrafish and carp brain: implications for cold acclimation

Calcium binding to sialic acids and its effect on the conformation of ependymins

Contact Info

Product

Resources

About