Identification of the thiamin pyrophosphokinase gene in rainbow trout: characteristic structure and expression of seven splice variants in tissues and cell lines and during embryo development.
Thiamin pyrophosphokinase (TPK) converts thiamin to its active form, thiamin diphosphate. In humans, TPK expression is down-regulated in some thiamin deficiency related syndrome, and enhanced during pregnancy. Rainbow trout are also vulnerable to thiamin deficiency in wild life and are useful models for thiamin metabolism research. We identified the tpk gene transcript including seven splice variants in the rainbow trout. Almost all cell lines and tissues examined showed co-expression of several tpk splice variants including a potentially major one at both mRNA and protein levels. However, relative to other tissues, the longest variant mRNA expression was predominant in the ovary and abundant in embryos. During embryogenesis, total tpk transcripts increased abruptly in early development, and decreased to about half of the peak shortly after hatching. In rainbow trout, the tpk transcript complex is ubiquitously expressed for all tissues and cells examined, and its increase in expression could be important in the early-middle embryonic stages. Moreover, decimated tpk expression in a hepatoma cell line relative to hepatic and gonadal cell lines appears to be consistent with previously reported down-regulation of thiamin metabolism in cancer.
Department of Fisheries & Wildlife, Michigan State University, East Lansing, 48824, USA.
Shinya
S
Yuge
Catherine A
CA
Richter
Maureen K
MK
Wright-Osment
Diane
D
Nicks
Stephanie K
SK
Saloka
Donald E
DE
Tillitt
Weiming
W
Li
D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss; D012326:RNA Splicing / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013836:Thiamin Pyrophosphokinase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D013836:Thiamin Pyrophosphokinase