Doc2: a novel brain protein having two repeated C2-like domains.
Two repeated C2-like domains interacting with Ca2+ and phospholipid are found in synaptotagmin and Rabphilin-3A which are implicated in neurotransmitter release. Here we have isolated a cDNA encoding a novel protein having two repeated C2-like domains from a human brain cDNA library. The isolated cDNA encodes a protein with 400 amino acids and a M(r) of 44,071. The purified recombinant protein indeed interacts with Ca2+ and phospholipid. We have named this protein Doc2 (Double C2). Doc2 is exclusively expressed in brain and is highly concentrated in the synaptic vesicle fraction. These results suggest that Doc2 is a novel brain protein and serves as a Ca2+ sensor in neurotransmitter release.
Orita
S
S
Shionogi Institute for Medical Science, Settsu, Japan.
Sasaki
T
T
Naito
A
A
Komuro
R
R
Ohtsuka
T
T
Maeda
M
M
Suzuki
H
H
Igarashi
H
H
Takai
Y
Y
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004926:Escherichia coli; D019204:GTP-Binding Proteins / Q000737:chemistry; D015723:Gene Library; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D009928:Organ Specificity; D010743:Phospholipids / Q000378:metabolism; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000302:isolation & purification / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid; D017386:Sequence Homology, Amino Acid; D013572:Synaptic Vesicles / Q000378:metabolism; D050857:Synaptotagmins; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins; D000097624:Rabphilin-3A
D048868:Adaptor Proteins, Signal Transducing; D002118:Calcium; D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D019204:GTP-Binding Proteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D009838:Oligodeoxyribonucleotides; D010743:Phospholipids; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D050857:Synaptotagmins; D033921:Vesicular Transport Proteins; D020691:rab GTP-Binding Proteins; D000097624:Rabphilin-3A; C091524:DOC2A protein, human; C490420:DOC2B protein, human