Agrin is a heparan sulfate proteoglycan involved in the development of the neuromuscular junction during embryogenesis. In addition to this well- characterized function, agrin may have additional functions in other tissues and during other stages in development. In this study we present the cDNA sequence of human agrin, and demonstrate a high agrin content in adult basement membranes. The N-terminal domain of human agrin is highly similar to that of chick agrin, suggesting a similar function in laminin binding. The presence of three SGXG sequences supports serine-linked glycosylation of the core protein, two sites being particularly favorable for heparan sulfate attachment. Comparison of levels of agrin mRNA in fetal and adult human tissues showed a remarkable upregulation in adult kidney and lung. In both tissues truncated agrin transcripts were detected, lacking the region that encodes the laminin-binding domain. The high transcription levels in lung and kidney corresponded with the accumulation of agrin in the alveolar and glomerular basement membranes, suggesting a filtration-associated function. These data provide new directions for investigating the role of agrin in its different physiological environments, including the basement membranes of the neuromuscular junction, kidney and lung.
|Number of pages||6|
|Journal||European Journal of Biochemistry|
|Publication status||Published - 15 May 1998|
- Alveolar basement membrane
- Glomerular basement membrane
- Heparan sulfate proteoglycan
- Neuromuscular junction