BEGAIN (brain-enriched guanylate kinase-associated protein), a novel neuronal PSD-95/SAP90-binding protein.
PSD-95/SAP90 is a synaptic membrane-associated guanylate kinase with three PDZ, one SH3, and one guanylate kinase (GK) domain. PSD-95/SAP90 binds various proteins through the PDZ domains and organizes synaptic junctions. PSD-95/SAP90 also interacts with the postsynaptic density (PSD) fraction-enriched protein, named SAPAP (also called GKAP and DAP), through the GK domain. SAPAP is Triton X-100-insoluble and recruits PSD-95/SAP90 into the Triton X-100-insoluble fraction in the transfected cells, suggesting that SAPAP may fix PSD-95/SAP90 to the PSD. Here we report a novel protein interacting with the GK domain of PSD-95/SAP90, BEGAIN. BEGAIN is specifically expressed in brain and enriched in the PSD fraction. BEGAIN is Triton X-100-soluble in the transfected cells but is recruited to the Triton X-100-insoluble fraction by SAPAP when coexpressed with PSD-95/SAP90. BEGAIN may be a novel PSD component associated with the core complex of PSD-95/SAP90 and SAPAP.
Deguchi
M
M
Takai Biotimer Project, ERATO, Japan Science and Technology Corporation, c/o JCR Pharmaceuticals Co. Ltd., 2-2-10 Murotani, Nishi-ku, Kobe 651-2241, Japan.
Hata
Y
Y
Takeuchi
M
M
Ide
N
N
Hirao
K
K
Yao
I
I
Irie
M
M
Toyoda
A
A
Takai
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000076122:Disks Large Homolog 4 Protein; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D000074407:SAP90-PSD95 Associated Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics; D013347:Subcellular Fractions / Q000378:metabolism
D002352:Carrier Proteins; D000076122:Disks Large Homolog 4 Protein; C501449:Dlg4 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D000074407:SAP90-PSD95 Associated Proteins; C033652:postsynaptic density proteins