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Mouse fibroblasts null for the long isoform of ?1,4-galactosyltransferase-I show defective cell-matrix interactions.

ABSTRACT: ?1,4 Galactosyltransferase-I (GalT-I) is expressed as two nearly identical polypeptides that differ only in the length of their cytoplasmic domains. The longer isoform has been implicated as a cell surface receptor for extracellular glycoside ligands, such as laminin. To more stringently test the function of the long GalT-I isoform during cell interactions with laminin, we created multiple independent fibroblastic cell lines that fail to express the long isoform, but which express the short GalT-I isoform normally and appear to have normal intracellular galactosylation. Cells devoid of the long GalT-I isoform are unable to adhere and spread on laminin substrates as well as control cells, but retain near normal interactions with fibronectin, which do not rely upon surface GalT-I function. The loss of the long GalT-I isoform also leads to a loss of actin stress fibers, focal adhesions and rac GTPase activation.

SUBMITTER: Elder BH

PROVIDER: S-EPMC5021623 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature

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Mouse fibroblasts null for the long isoform of β1,4-galactosyltransferase-I show defective cell-matrix interactions.

Elder Brooke H BH Shur Barry D BD

Biochemical and biophysical research communications 20160820 3

β1,4 Galactosyltransferase-I (GalT-I) is expressed as two nearly identical polypeptides that differ only in the length of their cytoplasmic domains. The longer isoform has been implicated as a cell surface receptor for extracellular glycoside ligands, such as laminin. To more stringently test the function of the long GalT-I isoform during cell interactions with laminin, we created multiple independent fibroblastic cell lines that fail to express the long isoform, but which express the short GalT ...[more]

PMID: 27553271

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