Article

Activation of multidrug efflux transporter activity at fertilization in sea urchin embryos (Strongylocentrotus purpuratus). Dev Biol

Hopkins Marine Station, Stanford University, 120 Oceanview Boulevard, Pacific Grove, CA 93950, USA.
Developmental Biology (Impact Factor: 3.55). 01/2005; 276(2):452-62. DOI: 10.1016/j.ydbio.2004.09.013
Source: PubMed

ABSTRACT

This study presents functional and molecular evidence for acquisition of multidrug transporter-mediated efflux activity as a consequence of fertilization in the sea urchin. Sea urchin eggs and embryos express low levels of efflux transporter genes with homology to the multidrug resistance associated protein (mrp) and permeability glycoprotein (p-gp) families of ABC transporters. The corresponding efflux activity is low in unfertilized eggs but is dramatically upregulated within 25 min of fertilization; the expression of this activity does not involve de novo gene expression and is insensitive to inhibitors of transcription and translation indicating activation of pre-existing transporter protein. Our study, using specific inhibitors of efflux transporters, indicates that the major activity is from one or more mrp-like transporters. The expression of activity at fertilization requires microfilaments, suggesting that the transporters are in vesicles and moved to the surface after fertilization. Pharmacological inhibition of mrp-mediated efflux activity with MK571 sensitizes embryos to the toxic compound vinblastine, confirming that one role for the efflux transport activity is embryo protection from xenobiotics. In addition, inhibition of mrp activity with MK571 alone retards mitosis indicating that mrp-like activity may also be required for early cell divisions.

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    • "Such anomalies induced by BPA may have aggravating effect on the activity of transporter proteins that are " inherited " from mother at this embryonic stage and not zygotically-expressed. After sea urchin eggs fertilization, actin polymerization enables microfilament-mediated process of transportation of ABC transporter proteins enclosed in vesicles, which are further inserted in the cell membrane and activated (Hamdoun et al., 2004). This process of protein transportation is crucial for the integrity of actin in fertilized urchin eggs, because it enables activation of MXR mechanisms when the embryos relies only on maternal proteins. "
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    • "Such anomalies induced by BPA may have aggravating effect on the activity of transporter proteins that are " inherited " from mother at this embryonic stage and not zygotically-expressed. After sea urchin eggs fertilization, actin polymerization enables microfilament-mediated process of transportation of ABC transporter proteins enclosed in vesicles, which are further inserted in the cell membrane and activated (Hamdoun et al., 2004). This process of protein transportation is crucial for the integrity of actin in fertilized urchin eggs, because it enables activation of MXR mechanisms when the embryos relies only on maternal proteins. "

    Full-text · Dataset · Aug 2014
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    • "Such anomalies induced by BPA may have aggravating effect on the activity of transporter proteins that are " inherited " from mother at this embryonic stage and not zygotically-expressed. After sea urchin eggs fertilization, actin polymerization enables microfilament-mediated process of transportation of ABC transporter proteins enclosed in vesicles, which are further inserted in the cell membrane and activated (Hamdoun et al., 2004). This process of protein transportation is crucial for the integrity of actin in fertilized urchin eggs, because it enables activation of MXR mechanisms when the embryos relies only on maternal proteins. "

    Full-text · Dataset · Aug 2014
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