Characterization of a ribonucleic acid transcript from the brook trout (Salvelinus fontinalis) ovary with structural similarities to mammalian adipsin/complement factor D and tissue kallikrein, and the effects of kallikrein-like serine proteases on follicle contraction.
A 2.4-kilobase (kb) clone (kallikrein trout #14; KT-14) was isolated from a brook trout ovulatory cDNA library. KT-14 contains an open reading frame (ORF) of 768 base pairs (bp), presumably encoding a protein of 255 amino acids. The KT-14 cDNA also contains a 711 -bp 5' untranslated region and a 793-bp region downstream of the ORF that includes a 66-bp sequence repeated 12 times. The amino acid sequence of the KT-14 ORF is 41 % identical to that of porcine complement factor D and 33% identical to that of porcine pancreatic kallikrein. On Northern blots of ovarian tissue, KT-14 hybridized with four transcripts of 1.8, 2.4, 2.9, and 3.2 kb. While the 3.2- and 2.4-kb transcripts were present in the ovary prior to meiotic maturation, they were significantly up-regulated at ovulation and at 12 h postovulation, respectively. Antibodies constructed against the recombinant KT-14 protein recognized one 30-kDa immunogenic protein in ovarian tissue and fluid. This immunogenic protein was significantly elevated in the tissue by ovulation. Using a follicle weight loss bioassay, we provide indirect evidence that mammalian kallikrein and related serine proteases can stimulate brook trout follicle contraction. Thus, one possible function of the KT-14 protein may be the regulation of oocyte expulsion at ovulation.
Hajnik
C A
CA
University of Notre Dame, Department of Biological Sciences, Indiana 46556, USA.
Goetz
F W
FW
Hsu
S Y
SY
Sokal
N
N
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002918:Chymotrypsin / Q000494:pharmacology; D011416:Complement Factor D / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry; D005260:Female; D007610:Kallikreins / Q000235:genetics* / Q000494:pharmacology; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D006080:Ovarian Follicle / Q000187:drug effects* / Q000502:physiology; D010053:Ovary / Q000737:chemistry*; D012333:RNA, Messenger / Q000737:chemistry*; D017385:Sequence Homology; D012697:Serine Endopeptidases / Q000235:genetics*; D020840:Tissue Kallikreins; D014337:Trout / Q000235:genetics*; D014357:Trypsin / Q000494:pharmacology
D018076:DNA, Complementary; D012333:RNA, Messenger; D007610:Kallikreins; D012697:Serine Endopeptidases; D002918:Chymotrypsin; D020840:Tissue Kallikreins; D014357:Trypsin; D011416:Complement Factor D