Deduced primary structure of vitellogenin in the giant freshwater prawn, Macrobrachium rosenbergii, and yolk processing during ovarian maturation.
A cDNA encoding vitellogenin (Vg) in the giant freshwater prawn, Macrobrachium rosenbergii, was cloned based on the cDNA sequence of vitellin (Vn) fragments A-N and B-42 determined previously, and its amino acid sequence deduced. The open reading frame (ORF) encoded 2,537 amino acid residues and its deduced amino acid sequence possessed three consensus cleavage sites, R-X-R-R, similar to those reported in Vgs of insects. The deduced primary structure of Vg in M. rosenbergii was seen to be similar to that of Penaeus japonicus, especially in the N-terminal region. It is therefore likely that Vgs in crustacean species including prawns and other related decapods exhibit a similar structural pattern. Based on the deduced primary structure of Vg and analysis of the various Vg and Vn subunits found in the hemolymph and ovary during ovarian maturation, we demonstrated the post-translational processing of Vg in M. rosenbergii. This is the first time that Vg processing has been clearly demonstrated in a crustacean species. Vg, after being synthesized in the hepatopancreas, is considered to be cleaved by a subtilisin-like endoprotease to form two subunits, A and proB, which are then released into the hemolymph. In the hemolymph, proB is possibly cleaved by a processing enzyme of unknown identity to give rise to subunits B and C/D. The three processed subunits A, B, and C/D are sequestered by the ovary to give rise to three yolk proteins, Macr-VnA, VnB, and VnC/D.
Okuno
Atsuro
A
Japan International Research Center for Agricultural Sciences, Tsukuba, Ibaraki 305-8686, Japan.
Yang
Wei-Jun
WJ
Jayasankar
Vidya
V
Saido-Sakanaka
Hisako
H
Huong
Do Thi Thanh
DT
Jasmani
Safiah
S
Atmomarsono
Muharijadi
M
Subramoniam
Thanumalayaperumal
T
Tsutsui
Naoaki
N
Ohira
Tsuyoshi
T
Kawazoe
Ichiro
I
Aida
Katsumi
K
Wilder
Marcy N
MN
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics*; D005260:Female; D006458:Hemolymph / Q000737:chemistry; D008969:Molecular Sequence Data; D010053:Ovary / Q000737:chemistry / Q000254:growth & development*; D033541:Palaemonidae / Q000502:physiology*; D016133:Polymerase Chain Reaction; D014819:Vitellogenins / Q000737:chemistry*
D017931:DNA Primers; D018076:DNA, Complementary; D014819:Vitellogenins