Format

Send to

Choose Destination
Biochemistry. 2003 Nov 11;42(44):13035-48.

Transmembrane domain analysis of polycystin-1, the product of the polycystic kidney disease-1 (PKD1) gene: evidence for 11 membrane-spanning domains.

Author information

1
Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, Kansas 66160-7421, USA.

Abstract

Polycystin-1, the protein product of the polycystic kidney disease-1 (PKD1) gene, was originally predicted to be an integral membrane glycoprotein with 11 transmembrane (TM) domains (TM 1-11). Subsequent comparative sequence analyses led to a revision of the original model, which retained the overall topology and 11 TM segments (TM I-XI) but dropped 3 of the original domains and introduced 3 new TM domains. The membrane-spanning potential and the orientation of each of the proposed TM domains following the extracellular REJ domain (TM I-XI and TM 11) have now been tested. Using a series of N-terminal polycystin TM-glycosylation reporter gene fusions expressed in vivo, we assayed N-linked glycosylation of the C-terminal glycosylation reporter as an indicator of TM domain presence and orientation. This approach has clearly demonstrated that 7 of the 12 TM domains tested function as membrane-spanning domains. In vitro analysis of the topogenic potential of the five remaining TM domains revealed that four of these also function as membrane-spanning domains, thus supporting an 11 TM structure for polycystin-1 comprised of TM domains I-XI. In addition, these studies suggest that the membrane insertion of TM domains I-IX occurs in a cotranslational and sequential manner, while multiple topogenic determinants appear to be required for the integration of the C-terminal-most TM segments of polycystin-1.

PMID:
14596619
DOI:
10.1021/bi035074c
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for American Chemical Society
Loading ...
Support Center