Molecular cloning of amphiglycan, a novel integral membrane heparan sulfate proteoglycan expressed by epithelial and fibroblastic cells.

Abstract

Abstract. We have synthesized an antisense oligonucleotide primer that matches a supposedly conserved sequence in messages for heparan sulfate proteoglycans with transmembrane orientations. With the aid of this primer we have amplified partial and selected fulllength copies of a message from human lung fibroblasts that codes for a novel integral membrane heparan sulfate proteoglycan. The encoded protein is 198 aminoacids long, with discrete cytoplasmic, transmembrane, and amino-terminal extracellular domains. Except for the sequences that represent putative heparan sulfate chain attachment sites, the extracellular domain of this protein has a unique structure. The transmembrane and cytoplasmic domains, in contrast, are highly similar to the corresponding domains of fibroglyean and syndecan, the two cell surface proteoglycans that figured as models for the design of the antisense primer. This similarity includes the conservation of four tyrosine residues, one immediately in front of the stop transfer sequence and three in the cytoplasmic segment, and of the most proximal and most distal cytoplasmic sequences. The eDNA detects a single 2.6-kb message in cultured human lung fibroblasts and in a variety of human epithelial and fibroblastie cell lines. Polyelonal and monoclonal antibodies raised against the encoded peptide after expression as a beta-galactosidase fusion protein react with the 35-kD coreprotein of a cell surface heparan sulfate proteoglycan of human lung fibroblasts and decorate the surface of many cell types. We propose to name this proteoglyean "amphiglycan" (from the Greek words amphi, "around, on both sides of" and amphoo, "both") referring to its domain structure which extends on both sides of the plasmamembrane, and to its localization around cells of both epithelial and fibroblastic origin.

Syndecan-1 and syndecan-4 can mediate the invasion of OpaHSPG-expressing Neisseria gonorrhoeae into epithelial cells

“…Among the cell lines analysed, we found that it was strongly expressed in the ME-180 cells and, to a signi®cantly lesser extent, in HeLa and MCF7 cells, whereas there is almost no expression in Chang, Hec-1B and HEp-2 cells. Expression of syndecan-2 (< 48 kDa in monomeric form and < 80 kDa in dimeric form) has been observed mainly in ®broblasts and endothelial cells (David et al, 1992b). Our results indicate that it is also strongly expressed in Chang and Hec-1B cells and, to a lesser extent, in MCF7 cells.…”

Induction of CCL13 expression in synovial fibroblasts highlights a significant role of oncostatin M in rheumatoid arthritis

“…Neutrophils, normal dermal fibroblasts, and RASFs were generated as described previously (33)(34)(35). Lung fibroblasts were kindly provided by P. Marynen (University of Leuven, Leuven, Belgium [36]), and the normal SFs and normal cervical fibroblasts were provided by E. Van de Leur (RWTH Aachen University Hospital, Aachen, Germany [37,38]). Primary human monocytes were isolated from fresh blood using the Dynal Monocyte Negative Isolation Kit as described by the manufacturer (Invitrogen).…”

PTPσ functions as a presynaptic receptor for the glypican-4/LRRTM4 complex and is essential for excitatory synaptic transmission

“…23). We then expressed either PTPσ wild-type (WT) or PTPσ-AAAA in HEK293T cells, treated the cells with heparinase III (hep III; 1 U/mL) for 2 h to remove the HS chains from PTPσ, and stained the cells with a monoclonal 3G10 antibody that reacts only with hep III-treated HS chains (25). We found that cells expressing PTPσ WT, but not PTPσ-AAAA, reacted to the 3G10 antibody (Fig.…”