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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have determined the pathways taken by the trunk neural crest of quail and examined the parameters that control these patterns of dispersion. Using antibodies that recognize migratory neural crest cells (HNK-1), we have found that the crest cells take three primary pathways: (1) between the ectoderm and somites, (2) within the intersomitic space and (3) through the anterior somite along the basal surface of the myotome. The parameters controlling dispersion patterns of neural crest cells are several. The pathways are filled with at least two adhesive molecules, laminin and fibronectin, to which neural crest cells adhere tenaciously in culture. The pattern of migration through the somite may be accounted for in part by the precocious development of the basal lamina of the dermamyotome in the anterior half of the somite; this basal lamina contains both fibronectin and laminin and the neural crest cells prefer to migrate on it. In contrast, the regions into which the crest cells do not invade are filled with relatively nonadhesive molecules such as chondroitin sulphate. Some of the pathways are filled with hyaluronic acid, which stimulates the migration of neural crest cells when they are cultured in three-dimensional gels, presumably by opening spaces. Neural crest cells are also constrained to stay within the pathways by basal laminae, which act as barriers and through which crest cells do not go. Therefore, crest pathways are probably defined by several redundant factors. The directionality of crest cell migration is probably due to contact inhibition, which can be demonstrated in tissue culture. Various grafting experiments have suggested that chemotaxis and haptotaxis do not play a role in controlling the dispersion of the crest cells away from the neural tube. We have documented the extraordinary ability of neural crest cells to disperse in the embryo, even when they are grafted into sites in which they would normally not migrate. We have evidence that the cells' production of plasminogen activator, a proteolytic enzyme, and also the minimal tractional force that crest cells exert on the substratum as they migrate, contribute to this migratory ability.
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PMID:Control of pathfinding by the avian trunk neural crest. 307 15

The glycosylation of tissue plasminogen activator (t-PA) obtained from the Bowes melanoma cell line was re-examined using methods of serial lectin affinity chromatography coupled with Bio-Gel P-4 gel filtration chromatography and exoglycosidase sequencing. This study clarified an earlier discrepancy in the literature and confirmed that the major complex N-linked glycans on Bowes t-PA that carry sialic acid as their sole charged group are bi-antennary, core fucosylated, with terminal N-acetylgalactosamine residues. We also report the characterization of a series of related and previously unidentified sialylated glycans. Further we show that Bowes t-PA expresses glucuronic acid/sulphate containing N-linked glycans and is recognized by anti-carbohydrate L2/HNK-1 monoclonal antibodies. The presence on Bowes t-PA of glycans associated primarily with the nervous system is consistent with its expression in a cell line of neuroectodermal origin.
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PMID:The glycosylation of Bowes melanoma tissue plasminogen activator: lectin mapping, reaction with anti-L2/HNK-1 antibodies and the presence of sulphated/glucuronic acid containing glycans. 868 84

A family of about 20 novel acidic bi- and tri-antennary N-glycans, amounting to almost half those expressed on Bowes melanoma tissue-plasminogen activator (t-PA) were found to possess Galbeta1-->4GlcNAcbeta1-->, sulfated and sialylated GalNAcbeta1-->4GlcNAcbeta1--> or sulfated GlcAbeta1--> 3Galbeta1-->4GlcNAcbeta1--> antennae, of which those containing sulfated GlcA, depicting the L2/HNK-1 carbohydrate epitope, were preferentially located on the 6 arm. A proportion of the glycans were highly charged, because of multiple and variously distributed sulfation, some of which was located on the fucosylated chitobiose core. Multiple expression of the L2/HNK-1 epitope on a single glycan was observed. The most abundant compound was a biantennary glycan carrying sulfated GlcA on the 6-branched antenna and an alpha2-->6 sialylated GalNAc on the other. The N-glycosylation sequon containing Asn448, which is known to express all of the sulfate-carrying N-glycans contains, unusually, an arginine residue. An electrostatic interaction between this cationic amino acid and the core-sulfate group of the N-glycan is proposed to reduce mobility of the carbohydrate in the region of the t-PA active site. Because of the 'brain-type' nature of the N-glycans described in this neuro-ectodermal cell line, the possibility of neural t-PA interacting with the L2/HNK-1-recognizing molecule, laminin, of the central nervous system extracellular matrix is discussed.
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PMID:A family of novel, acidic N-glycans in Bowes melanoma tissue plasminogen activator have L2/HNK-1-bearing antennae, many with sulfation of the fucosylated chitobiose core. 1145 1