A novel species-specific RNA related to alternatively spliced amyloid precursor protein mRNAs.
Using an S1 nuclease protection assay, we have identified a novel "variant" Amyloid Precursor Protein (APP) RNA in human brain which is 3-6-fold more abundant than APP-770, but less abundant than APP-751 or APP-695. This variant, referred to as amyloid precursor-related protein 365 (APRP-365), is not detected in mouse and rat brain RNAs. A 1.6 kilo-basepair cDNA clone corresponding to this variant APP RNA predicts the existence of a 365 amino acid protein that is similar to the amino-terminal end of APP-770 but lacks the beta-amyloid peptide and any hydrophobic transmembrane spanning domains. In a modified polymerase chain reaction (PCR), we used amplification of reverse transcribed mRNA to confirm and extend our S1 observations. Together, the features of APRP-365 suggest that the human variant is a soluble protein containing a Kunitz protease inhibitor domain.
Jacobsen
J S
JS
Central Nervous System Biological Research Department, American Cyanamid Company, Pearl River, NY 10965.
Muenkel
H A
HA
Blume
A J
AJ
Vitek
M P
MP
D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000096:biosynthesis*; D000818:Animals; D001483:Base Sequence; D001923:Brain Chemistry; D002478:Cells, Cultured; D004247:DNA / Q000302:isolation & purification; D015870:Gene Expression; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D012313:RNA / Q000302:isolation & purification / Q000378:metabolism*; D015347:RNA Probes; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D051381:Rats; D015719:Single-Strand Specific DNA and RNA Endonucleases; D013698:Templates, Genetic
D016564:Amyloid beta-Protein Precursor; D015345:Oligonucleotide Probes; D015347:RNA Probes; D012333:RNA, Messenger; D012313:RNA; D004247:DNA; D012194:RNA-Directed DNA Polymerase; D015719:Single-Strand Specific DNA and RNA Endonucleases