Differential splicing of the growth hormone-releasing hormone gene in rat placenta generates a novel pre-proGHRH mRNA that encodes a different C-terminal flanking peptide.
We have isolated and characterized a novel rat placental pre-proGHRH mRNA (pre-proGHRH-2 mRNA). This mRNA is generated by an alternative splicing process which results in the presence of an additional exon of 156 bp (designated exon 4.5) located between exons 4 and 5 of the previously reported hypothalamic and placental pre-proGHRH mRNA (pre-proGHRH-1 mRNA). Since the sequences encoding mature GHRH are included within exons 3 and 4, the processing of pre-proGHRH-2 would not affect the synthesis of mature GHRH but would generate a C-terminal peptide (designated GCTP-2) different from that previously reported in the hypothalamus and placenta (GCTP-1). The putative GCTP-2 has 64 amino acids, and the first 18 N-terminal residues are identical to those present in GCTP-1 (30 amino acids long). Pre-proGHRH-2 mRNA has not been detected in the hypothalamus.
Pérez-Riba
M
M
Departament de Genètica, Institut de Recerca Oncològica, Autovia, Barcelona, Spain. mpr@gm.iro.es
González-Crespo
S
S
Boronat
A
A
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017931:DNA Primers; D005260:Female; D015723:Gene Library; D013007:Growth Hormone-Releasing Hormone / Q000096:biosynthesis* / Q000235:genetics; D008969:Molecular Sequence Data; D010920:Placenta / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D011498:Protein Precursors / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D014158:Transcription, Genetic
D017931:DNA Primers; D011498:Protein Precursors; D012333:RNA, Messenger; C047524:pre-pro-growth hormone releasing factor; D013007:Growth Hormone-Releasing Hormone