Differential expression of SNAP-25 isoforms and SNAP-23 in the adrenal gland.
In the rat adrenal gland, we previously observed that SNAP-25 is not restricted to the plasmalemma in noradrenergic cells as it is in adrenergic cells, and hypothesized that SNAP-25 isoform expression is different in the two phenotypes. Expression of SNAP-25 isoforms and SNAP-23 was examined by immunoblotting, immunofluorescence, and RT-PCR. Amplifications of SNAP-25 mRNAs were combined with Southern hybridization, restriction enzyme analysis, and sequencing of cloned PCR products to compare SNAP-25 isoform expression in rat and bovine adrenal glands. SNAP-25 and SNAP-23 mRNA and protein are expressed in the glands; SNAP-23 is enriched in the adrenal cortex, whereas SNAP-25 is restricted to the adrenal medulla. Furthermore, high levels of SNAP-25 and low levels of SNAP-23 are observed in the PC12 cells, whereas both SNAP-25 and SNAP-23 are expressed in adrenal medullary cultures. In all extracts, the SNAP-23 mRNA corresponded to SNAP-23a. SNAP-25a is the major form expressed in rat adrenal glands (75%), as it is in PC12 cells (80%), but both SNAP-25a and SNAP-25b (40% vs. 60%) are expressed in bovine adrenal medulla in situ and in culture. In addition, an enriched population of adrenergic cells (93%) expressed a higher level of SNAP-25b (70%), suggesting that this isoform may not be restricted to fast neurotransmission.
Grant
N J
NJ
INSERM Unité 338, Biologie de la Communication Cellulaire, Strasbourg, France.
Hepp
R
R
Krause
W
W
Aunis
D
D
Oehme
P
P
Langley
K
K
D000311:Adrenal Glands / Q000737:chemistry* / Q000166:cytology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D002417:Cattle; D019439:Chromaffin Cells / Q000737:chemistry / Q000502:physiology; D004837:Epinephrine / Q000502:physiology; D005091:Exons; D015870:Gene Expression / Q000502:physiology; D007536:Isomerism; D008297:Male; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D009638:Norepinephrine / Q000502:physiology; D050766:Qb-SNARE Proteins; D050767:Qc-SNARE Proteins; D051381:Rats; D017208:Rats, Wistar; D015183:Restriction Mapping; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D050825:Synaptosomal-Associated Protein 25
D002352:Carrier Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D050766:Qb-SNARE Proteins; D050767:Qc-SNARE Proteins; C100493:SNAP23 protein, human; C494210:Snap25 protein, rat; D050825:Synaptosomal-Associated Protein 25; D009638:Norepinephrine; D004837:Epinephrine