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Nucleotide bindind by the synapse associated protein SAP90
Author(s) -
Kistner Ute,
Garner Craig C.,
Linial Michal
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)00030-d
Subject(s) - guanylate kinase , microbiology and biotechnology , biology , nucleotide , kinase , ras superfamily , biochemistry , superfamily , protein kinase a , guanine nucleotide exchange factor , gene , membrane protein , signal transduction , membrane , gtp' , enzyme
The rat synapse associated protein SAP90 is a member of a superfamily of potential guanylate kinases localized at cell‐cell contact sites. This superfamily includes the synapse associated protein SAP97, a close relative of SAP90, the Drosophila tumor suppressor gene product dlg ‐Ap, the mammalian zonula occludens proteins ZO‐1 and ZO‐2 and the erythrocyte protein p55. Here we show that SAP90 specifically binds GMP in the micromolar range while binding to ATP, GDP and ADP is at a much lower affinity (10–25 mM), whether or not binding is detected for other guanine and adenine nucleotides. No guanylate kinase activity of SAP90 was detected under our experimental conditions. The importance of the GMP binding capacity per se and an evolutionary role for conserving of the guanylate kinase domain in this superfamily are discussed.