Expression and characterization of the human YWK-II gene, encoding a sperm membrane protein related to the alzheimer betaA4-amyloid precursorprotein.
The YWK-II cDNA, RSD-2, encoding a sperm membrane protein was isolated from a rat testis cDNA expression library. Using the RSD-2 insert in combination with rapid amplification of cDNA ends (RACE), the corresponding human gene was isolated from a human testis cDNA expression library. The human testis cDNA, HSD-2, is 3654 bp in length and contains an open reading frame of 763 codons. Hydropathicity analysis showed that the deduced polypeptide is a single strand transmembrane protein. The deduced polypeptide has partial homology with the amyloid precursor protein (APP) and high homology with the amyloid precursor homologue, APLP2/APPH. The YWK-II gene was mapped and assigned to human chromosome locus: 11q24-25. Northern blotting of various human tissue RNAs using the HSD-2 cDNA as a probe showed that the gene is transcribed ubiquitously. The cytoplasmic domain of HSD-2 was expressed in Escherichia coli. In-vitro studies showed that the recombinant polypeptide bound to a GTP-binding protein (G(o)) and was phosphorylated by protein kinase C and cdc2 kinase. In mammalian F11 cells, the recombinant polypeptide was found to be coupled to G(o). Thus, the YWK-II component has the characteristics of a G(o)-coupled receptor and may be involved in G(o)-mediated signal transduction pathway. Protein kinase C and cdc2 kinase may regulate this pathway in spermatozoa by phosphorylating the cytoplasmic domain of the YWK-II component.
Huang
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P
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Faculty of Basic Medicine, Peking Union Medical College, 5 Dong Dan 3 Tiao, Beijing 100005.
Miao
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S
Fan
H
H
Sheng
Q
Q
Yan
Y
Y
Wang
L
L
Koide
S S
SS
D000544:Alzheimer Disease; D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000737:chemistry*; D001483:Base Sequence; D001665:Binding Sites; D002874:Chromosome Mapping; D002880:Chromosomes, Human, Pair 11; D003593:Cytoplasm / Q000378:metabolism; D018076:DNA, Complementary; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D019204:GTP-Binding Proteins / Q000378:metabolism; D015870:Gene Expression; D005982:Glutathione Transferase; D006160:Guanosine Triphosphate / Q000378:metabolism; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins; D010766:Phosphorylation; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics; D013094:Spermatozoa / Q000378:metabolism*; D013462:Sulfur Radioisotopes; D014018:Tissue Distribution
C489697:APLP1 protein, human; C084104:APLP2 protein, human; D016564:Amyloid beta-Protein Precursor; C498283:Aplp2 protein, rat; D018076:DNA, Complementary; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; D013462:Sulfur Radioisotopes; D006160:Guanosine Triphosphate; D005982:Glutathione Transferase; D019204:GTP-Binding Proteins; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D020962:Heterotrimeric GTP-Binding Proteins