Goodpasture antigen-binding protein and its spliced variant, ceramide transfer protein, have different functions in the modulation of apoptosis during zebrafish development.
Human Goodpasture antigen-binding protein (GPBP) is an atypical protein kinase that phosphorylates the Goodpasture auto-antigen, the alpha3 chain of collagen IV. The COL4A3BP gene is alternatively spliced producing two protein isoforms: GPBP and GPBPDelta26. The latter lacks a serine-rich domain composed of 26 amino acid residues. Both isoforms also function as ceramide transfer proteins (CERT). Here, we explored the function of Gpbp and GpbpDelta26/CERT during embryogenesis in zebrafish. We cloned both splice variants of the zebrafish gene and found that they are differentially expressed during development. We used antisense oligonucleotide-mediated loss-of-function and synthetic mRNA-based gain-of-function approaches. Our results show that the loss-of-function phenotype is linked to cell death, evident primarily in the muscle of the somites, extensive loss of myelinated tracks, and brain edema. These results indicate that disruption of the nonvesicular ceramide transport is detrimental to normal embryonic development of somites and brain because of increased apoptosis. Moreover, this phenotype is mediated by Gpbp but not GpbpDelta26/CERT, suggesting that Gpbp is an important factor for normal skeletal muscle and brain development.
Granero-Moltó
Froilán
F
Center for Matrix Biology, Department of Medicine, Biochemistry, and Pathology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
Sarmah
Swapnalee
S
O'Rear
Lynda
L
Spagnoli
Anna
A
Abrahamson
Dale
D
Saus
Juan
J
Hudson
Billy G
BG
Knapik
Ela W
EW
D017398:Alternative Splicing / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D001324:Autoantigens / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002460:Cell Line; D002518:Ceramides / Q000378:metabolism; D003001:Cloning, Molecular; D024141:Collagen Type IV / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008969:Molecular Sequence Data; D010641:Phenotype; D011485:Protein Binding; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
D001324:Autoantigens; D002518:Ceramides; D024141:Collagen Type IV; D018076:DNA, Complementary; D020033:Protein Isoforms; D012333:RNA, Messenger; D029961:Zebrafish Proteins; C057112:type IV collagen alpha3 chain; C530998:col4a3bpa protein, zebrafish; D017346:Protein Serine-Threonine Kinases