Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Galectin-1 (Gal1) was the first identified member of the galectin family of beta-galactosidase-binding proteins. Gal1 has important roles in processes fundamental to growth and survival of an organism, including cell adhesion, cell proliferation and apoptosis, and is expressed in many tissues, including the nervous system. In the 1980s, research focused on the developmental regulation of Gal1 expression during neurogenesis. Gal1 was found to be expressed mainly in peripherally-projecting neurons beginning early in neurogenesis, and its expression is maintained at high levels in subpopulations of these neurons in the adult rodent. Although the expression pattern of Gal1 implied that it may be involved in axonal guidance or targeting of subsets of sensory and motoneurons, possible roles of Gal1 in the nervous system had not been confirmed until recently. Gal1 has since been shown to be required for the proper guidance of subsets of primary olfactory axons (to targets in the olfactory bulb) and of primary somatosensory axons (to targets in the superficial dorsal horn). In addition, Gal1 has been implicated in the regenerative response of axons following peripheral nerve injury. Gal1 has been shown to promote axonal regeneration through the activation of macrophages. Also, Gal1 may act within the injured neuron to enhance regrowth: the injury-induced regulation of Gal1 in numerous types of peripherally- and centrally-projecting neurons correlates positively with the regenerative potential of their axons. In this review, we discuss the expression pattern of Gal1 in sensory and motoneurons, and the potential roles of Gal1 in development, axonal regeneration and neuropathic pain.
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PMID:Expression and functions of galectin-1 in sensory and motoneurons. 1602 60

We have established previously that the 67-kDa elastin-binding protein (EBP), identical to the spliced variant of beta-galactosidase, acts as a recyclable chaperone that facilitates secretion of tropoelastin. (Hinek, A., Keeley, F. W., and Callahan, J. W. (1995) Exp. Cell Res. 220, 312-324). We now demonstrate that EBP also forms a cell surface-targeted molecular complex with protective protein/cathepsin A and sialidase (neuraminidase-1), and provide evidence that this sialidase activity is a prerequisite for the subsequent release of tropoelastin. We found that treatment with sialidase inhibitors repressed assembly of elastic fibers in cultures of human skin fibroblasts, aortic smooth muscle cells, and ear cartilage chondrocytes and caused impaired elastogenesis in developing chick embryos. Fibroblasts derived from patients with congenital sialidosis (primary deficiency of neuraminidase-1) and galactosialidosis (secondary deficiency of neuraminidase-1) demonstrated impaired elastogenesis, which could be reversed after their transduction with neuraminidase-1 cDNA or after treatment with bacterial sialidase, which has a similar substrate specificity to human neuraminidase-1. We postulate that neuraminidase-1 catalyzes removal of the terminal sialic acids from carbohydrate chains of microfibrillar glycoproteins and other adjacent matrix glycoconjugates, unmasking their penultimate galactosugars. In turn, the exposed galactosugars interact with the galectin domain of EBP, thereby inducing the release of transported tropoelastin molecules and facilitating their subsequent assembly into elastic fibers.
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PMID:Lysosomal sialidase (neuraminidase-1) is targeted to the cell surface in a multiprotein complex that facilitates elastic fiber assembly. 1631 20

We report a detailed structural analysis of the N-glycans of Caenorhabditis elegans recognized by C. elegans galectin LEC-6. Glycoproteins of C. elegans captured by an immobilized LEC-6 affinity adsorbent were isolated. The N-glycans of these glycoproteins were then liberated by hydrazinolysis and labeled with the fluorophore 2-aminopyridine (PA). The derived pyridylaminated (PA)-sugars were further fractionated by rechromatography on immobilized LEC-6 adsorbent and by reversed-phase high-performance liquid chromatography (HPLC). The structures of the PA-sugars thus obtained were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS/MS) in conjunction with glycosidase digestion. We confirmed that all PA-sugars having affinity for LEC-6 contain a Gal-Fuc disaccharide unit, and that this unit is bound to the innermost GlcNAc residue of the N-glycan chain. The dissociation constants of LEC-6 for these glycans were measured by frontal affinity chromatography. LEC-6 exhibited higher affinity for oligosaccharides having a Gal-Fuc unit linked to position 6 of the innermost GlcNAc residue than for those having Galbeta1-4GlcNAc units. Affinity for the former disappeared, however, following treatment with beta-galactosidase. If the glycan contained a Hex-Fuc disaccharide linked to the penultimate GlcNAc residue, the affinity would be diminished. We propose, therefore, that the galectins of C. elegans utilize the Gal-Fuc disaccharide unit for recognition instead of the Gal-GlcNAc unit that is common in vertebrates.
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PMID:Caenorhabditis elegans N-glycans containing a Gal-Fuc disaccharide unit linked to the innermost GlcNAc residue are recognized by C. elegans galectin LEC-6. 1869 18

Cardiopulmonary dirofilariosis (Dirofilaria immitis) is characterized by apparent contradictory events, like the long-term survival of adult worms in the circulatory system of the infected hosts and the development of life-threatening events like thromboembolisms and others. Thus parasite mechanisms, like the activation of fibrinolytic system, are key to the survival of both the worms and the host. The aim of this study was to investigate the interaction between D. immitis adult worms surface-associated antigens (DiSAA) and the fibrinolytic system of the host. We demonstrate that DiSAA extract is able to bind plasminogen and generate plasmin, with the latter occurring in a tissue plasminogen activator (t-PA) dependent manner. Additionally, 11 plasminogen-binding proteins from DiSAA extract were identified by proteomics and mass spectrometry (MS) (actin-5C, actin-1, enolase, fructose-bisphosphate aldolase, GAPDH, MSP domain protein, MSP 2, beta-galactosidase-binding-lectin, galectin, immunoglobulin I-set domain-containing protein and cyclophilin Ovcyp-2). Because in a previous work we have shown the positive interaction between the excretory/secretory antigens of D. immitis (DiES) and the host fibrinolytic system and many of the molecules identified here are shared by both antigens, we hypothesize that DiSAA cooperate in host fibrinolytic system activation promoting the fibrin clot lysis.
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PMID:Surface associated antigens of Dirofilaria immitis adult worms activate the host fibrinolytic system. 2343 49