Developmentally regulated proteolytic processing of a yolk glycoprotein complex in embryos of the sea urchin, Strongylocentrotus purpuratus

Lee, Geoffrey F.; Fanning, Elinor W.; Small, Maureen P.; Hille, Merrill B.

doi:10.1016/0922-3371(89)90779-x

Cited by 17 publications

(8 citation statements)

References 23 publications

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“…Vt is stored and consumed in the egg, whereas its precursor Vg is synthesized maternally in the fat body (Wahli, 1988;Raikhel and Dhadialla, 1992). One of the early events during embryo development is initiation of proteolytic processing of Vt (Purcell et al, 1988;Lee et al, 1989). Overall regulation of the processing is unclear but a growing body of evidence (Nordin et al, 1991;Fagotto, 1991;Mallya et al, 1992;Fagotto and Maxfield, 1994) indicates that yolk granule acidification may play a role in its activation.…”

Section: Introductionmentioning

confidence: 94%

Localization of the proenzyme form of the vitellin-processing protease inBlattella germanica by affinity-purified antibodies

Liu

Nordin

1998

Arch. Insect Biochem. Physiol.

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Section: Introductionmentioning

confidence: 94%

Localization of the proenzyme form of the vitellin-processing protease inBlattella germanica by affinity-purified antibodies

Liu

Nordin

1998

Arch. Insect Biochem. Physiol.

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“…4). MYP occurs as a single species of 200 kDa in coelomic fluid that is processed into several distinct smaller fragments in yolk platelets once within the egg (Kari and Rottman, 1985;Armant et al, 1986;Scott and Lennarz, 1989;Lee et al, 1989). This processing is concomitant with the acidification of yolk platelets that occurs during embryogenesis and since many transferrins release iron at low pH, MYP processing may be linked to iron release from this protein.…”

Section: Myp Binds Ironmentioning

confidence: 99%

“…Its deposition there accounts for more than 10 -15% of the total egg protein (Ichio et al, 1978;Kari and Rottman, 1980;Ozaki, 1980;Harrington and Easton, 1982). During embryogenesis MYP is processed into characteristic lower molecular weight cleavage products that disappear by the pluteus stage (Kari and Rottman, 1985;Armant et al, 1986;Scott and Lennarz, 1989;Lee et al, 1989), although the significance of this processing is unclear.…”

Section: Introductionmentioning

confidence: 99%

The Major Yolk Protein in Sea Urchins Is a Transferrin-like, Iron Binding Protein

Brooks

Wessel

2002

Developmental Biology

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The major yolk protein (MYP) in sea urchins has historically been classified as a vitellogenin based on its abundance in the yolk platelets. Curiously, it is found in both sexes of sea urchins where it is presumed to play a physiological role in gametogenesis, embryogenesis, or both. Here we present the primary structure of MYP as predicted from cDNAs of two sea urchins species, Strongylocentrotus purpuratus and Lytechinus variegatus. The sequence from these two species share identity to one another, but bear no resemblance to other known vitellogenins. Instead the sequence shares identity to members of the transferrin superfamily of proteins. In vitro iron binding assays, including both (59)Fe overlay assays of MYP enriched coelomic fluid and immunoprecipitation of native iron-bound MYP from coelomic fluid, support this classification. We suggest that one of MYP's transferrin-like properties is to shuttle iron to developing germ cells.

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“…We estimate a 20‐fold reduction of YP30 from egg to pluteus. By comparison, MYP decreases in total abundance similarly, but goes through a characteristic series of proteolytic degradation (see, for example, Lee et al 1989 ; Scott & Lennarz 1989). Thus, YP30 and MYP appear to decrease similarly in levels of abundance.…”

Section: Resultsmentioning

confidence: 99%

Direct molecular interaction of a conserved yolk granule protein in sea urchins

et al. 2000

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The regulation of yolk storage in oocytes and subsequent utilization in embryos is critical for embryogenesis. In sea urchins, the major yolk protein is made in the intestines, transported to the ovaries and accumulated in developing oocytes within membrane‐bound vesicles comprising approximately 10% of the mass of an egg. Here, a non‐yolk protein that accumulates specifically in yolk granules is reported. This protein was identified by cDNA cloning and, by use of antibodies to the recombinant protein, it was shown that this molecule is stored selectively in yolk granules of oocytes and embryos. No accumulation was seen in the accessory cells, testis, or intestines. In situ ribonucleic acid (RNA) hybridizations showed that the transcript accumulated only in oocytes, and was more highly concentrated in young oocytes. However, later in oogenesis, the messenger ribonucleic acid (mRNA) levels decreased significantly so that no signal was detectable in mature haploid eggs or at any later stage in development. However, by immunofluorescence and western blot analysis, the 30 kDa band was present throughout development. The predicted sequence of this protein shows that it is a member of the bep, HLC‐32, EBP family of sea urchin proteins, but as it does not accumulate at the cell surface, nor in the hyaline layer in the two species studied here, as do other members of the family, it has been referred to as YP30 (30 kDa protein of the yolk platelet). To address its potential function, yeast two‐hybrid analysis was performed to screen for proteins that potentially interact with YP30. It was found that it binds itself, and forms strongly interacting dimers. It is hypothesized that YP30 participates in the packaging and storage of major yolk protein during oogenesis, or in the utilization of the major yolk protein in development.

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Developmentally regulated proteolytic processing of a yolk glycoprotein complex in embryos of the sea urchin, Strongylocentrotus purpuratus

Cited by 17 publications

References 23 publications

Localization of the proenzyme form of the vitellin-processing protease inBlattella germanica by affinity-purified antibodies

Localization of the proenzyme form of the vitellin-processing protease inBlattella germanica by affinity-purified antibodies

The Major Yolk Protein in Sea Urchins Is a Transferrin-like, Iron Binding Protein

Direct molecular interaction of a conserved yolk granule protein in sea urchins

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