Cleavage site of a major yolk protein (MYP) determined by cDNA isolation and amino acid sequencing in sea urchin, Hemicentrotus pulcherrimus

Yokota, Yukio; Unuma, Tatsuya; Moriyama, Akihiko; Yamano, Keisuke

doi:10.1016/s1096-4959(03)00084-8

Cited by 42 publications

(25 citation statements)

References 28 publications

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“…These structures probably fill the growing autophagic vacuole with a lytic substance. Indeed, the presence of hydrolytic ferments has been demonstrated for at least the cortical and yolk granules of sea urchin eggs (Haley and Wessel, 1999;Murray et al, 2000;Yokota et al, 2003). It is probable that the granules present in the oocytes of P. ochraceus also contain hydrolases.…”

Section: Discussionmentioning

confidence: 99%

An ultrastructural study of oocyte atresia in the starfish Pisaster ochraceus

Reunov

Crawford

2010

Zoology

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Section: Discussionmentioning

confidence: 99%

An ultrastructural study of oocyte atresia in the starfish Pisaster ochraceus

Reunov

Crawford

2010

Zoology

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“…Yolk endocytosis systems in many organisms have been compared with the best-studied endocytosis pathways, such as those of mammalian LDLs and transferrin [41]. MYP belongs to the transferrin superfamily, and its packaging into yolk may serve as an iron reserve during embryogenesis [6,7]. MYP's receptor has yet to be identified, but endocytic trafficking of this protein is thought to proceed through pathways similar to those used by transferrin in somatic cells [1,41].…”

Section: Discussionmentioning

confidence: 99%

“…There it is packaged into the YP30 yolk platelets, where it accumulates to 10-15% of the total egg protein [4,5]. MYP belongs to the transferrin superfamily [6,7], although its receptor has yet to be identified.…”

Section: Introductionmentioning

confidence: 99%

The Major Yolk Protein of Sea Urchins Is Endocytosed by a Dynamin-Dependent Mechanism1

Brooks¹,

Wessel²

2004

Biology of Reproduction

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Sea urchin oocytes grow to 10 times their original size during oogenesis by both synthesizing and importing a specific repertoire of proteins to drive fertilization and early embryogenesis. During the vitellogenic growth period, the major yolk protein (MYP), a transferrin-like protein, is synthesized in the gut, transported into the ovary, and actively endocytosed by the oocytes. Here, we begin to dissect this mechanism by first testing the hypothesis that MYP endocytosis is dynamin-dependent. We have identified a sea urchin dynamin cDNA that is highly similar in amino acid sequence, structure, and size to mammalian dynamin I: it contains an N-terminal GTPase domain, a pleckstrin-homology domain, and a C-terminal proline-rich domain. Sea urchin dynamin is enriched at the cortex of oocytes and colocalizes to MYP endocytic vesicles at the oocyte periphery. To test for a functional relationship between MYP endocytosis and dynamin, we used a dominant-negative human dynamin I mutant protein containing an alteration within the GTPase domain (hDyn(K44A)) to specifically compete for dynamin function. Using a fluorescent MYP construct to follow its endocytosis solely, as well as a general endocytosis marker, we demonstrate that the disruption of dynamin function significantly reduces MYP uptake but does not affect fluid-phase endocytosis. Using this specific biochemical approach, we are able to separate distinct pathways of endocytosis during oogenesis and learn that dynamin-mediated endocytosis is responsible for MYP endocytosis but not fluid-phase uptake.

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“…In certain taxa they become involved for example in calcium or ferric metabolism (Abdu et al 2002;.Yokota et al 2003). In crustaceans, vitellin protein has been purified and characterized in eggs from several species including decapods, e.g., C. quadricarinatus (Sagi et al 1996), Palaemon elegans Rathke, 1837 (Sanders et al 2005), M. rosenbergii (Lee et al 1997)), copepod Amphiascus tenuiremis Brady et D. Robertson, 1875 (Volz & Chandler 2004), barnacle Balanus amphitrite Darwin, 1854 (Billinghurst et al 2000), mysid Neomysis integer (Ghekiere et al 2005), and amphipod Leptocheirus plumulosus Shoemaker, 1932 (Volz et al 2002).…”

Section: Gonadsmentioning

confidence: 99%

Endocrine regulation of the reproduction in crustaceans: Identification of potential targets for toxicants and environmental contaminants

et al. 2008

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Progress in ecotoxicological research documents that crustaceans are highly vulnerable to diverse chemicals and toxicants in the environment. In particular, pollutants affecting endocrine homeostasis in crustaceans (i.e., endocrine disruptors) are intensively studied, and serious reproductive disorders have been documented. In this review, current knowledge about the endocrine regulation of the crustacean reproduction is put together with the published ecotoxicological data with an attempt to summarize the potential of xenobiotics to affect crustacean reproduction. Following gaps and trends were identified: (1) Studies are required in the field of neurohormone (serotonin and dopamine) regulation of the reproduction and possible modulations by environmental toxicants such as antidepressant drugs. (2) Molting-related parameters (regulated by ecdysteroid hormones) are closely coordinated with the development and reproduction cycles in crustaceans (cross-links with methyl farnesoate signalling), and their susceptibility to toxicants should be studied. (3) Other biochemical targets for xenobiotics were recently discovered in crustaceans and these should be explored by further ecotoxicological studies (e.g., new information about ecdysteroid receptor molecular biology). (4) Some sex steroid hormones known from vertebrates (testosterone, progesterone) have been reported in crustaceans but knowledge about their targets (crustacean steroid receptors) and signalling is still limited. (5) Determination of the sex in developing juveniles (affecting the sex ratio in population) is a sensitive parameter to various xenobiotics (including endocrine disruptors) but its modulation by general environmental stress and non-specific toxicity should be further studied.

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Cleavage site of a major yolk protein (MYP) determined by cDNA isolation and amino acid sequencing in sea urchin, Hemicentrotus pulcherrimus

Cited by 42 publications

References 28 publications

An ultrastructural study of oocyte atresia in the starfish Pisaster ochraceus

An ultrastructural study of oocyte atresia in the starfish Pisaster ochraceus

The Major Yolk Protein of Sea Urchins Is Endocytosed by a Dynamin-Dependent Mechanism1

Endocrine regulation of the reproduction in crustaceans: Identification of potential targets for toxicants and environmental contaminants

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