Faculty Collaboration Database

The bovine mannose 6-phosphate/insulin-like growth factor II receptor. The role of arginine residues in mannose 6-phosphate binding. J Biol Chem 1993 Mar 15;268(8):5457-63

Date

03/15/1993

Pubmed ID

8449908

Scopus ID

2-s2.0-0027471426 (requires institutional sign-in at Scopus site)   96 Citations

Abstract

The extracytoplasmic region of the bovine cation-independent mannose 6-phosphate/insulin-like growth factor II receptor (M6P/IGF-II receptor) consists of 15 homologous repeating domains, each of which is approximately 147 residues in length. The receptor contains two high affinity mannose 6-phosphate (Man-6-P) binding sites and our recent studies (Westlund, B., Dahms, N. M., and Kornfeld, S. (1991) J. Biol. Chem. 266, 23233-23239) have localized these two binding sites to domains 1-3 and 7-11. To further define the location of the Man-6-P binding sites and to determine the role of specific arginine residues in Man-6-P binding, site-directed mutagenesis was utilized to create truncated soluble forms of the M6P/IGF-II receptor in conjunction with either conservative (Lys) or nonconservative (Ala) replacement of arginine residues. These mutants were expressed transiently in COS-1 cells and assayed for their ability to bind phosphomannosyl residues by affinity chromatography. Analysis of the ligand binding activity of carboxyl-terminal truncated forms of the receptor's extracytoplasmic region demonstrated that the second Man-6-P binding site is contained within domains 7-9. Substitution of Arg435 in domain 3 of the amino-terminal binding site and Arg1334 in domain 9 of the second binding site results in a dramatic loss of ligand binding activity. However, substitutions at positions 435 and/or 1334 did not affect the secretion, glycosylation, or immunoreactivity of these truncated proteins. Taken together, these results indicate that Arg435 and Arg1334 are essential components of the M6P/IGF-II receptor's high affinity Man-6-P binding sites.

Author List

Dahms NM, Rose PA, Molkentin JD, Zhang Y, Brzycki MA

Author

Nancy M. Dahms PhD Professor in the Biochemistry department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Amino Acid Sequence
Animals
Arginine
Base Sequence
Binding Sites
Cattle
Cell Line, Transformed
Chromatography, Affinity
DNA
Mannosephosphates
Molecular Sequence Data
Mutagenesis, Site-Directed
Receptor, IGF Type 2
Sequence Homology, Amino Acid