Regulation of Drosophila vasa in vivo through paralogous cullin-RING E3 ligase specificity receptors

TY - JOUR

T1 - Regulation of Drosophila vasa in vivo through paralogous cullin-RING E3 ligase specificity receptors

AU - Kugler, Jan-Michael

AU - Woo, Jae-Sung

AU - Oh, Byung-Ha

AU - Lasko, Paul

PY - 2010/4

Y1 - 2010/4

N2 - In Drosophila species, molecular asymmetries guiding embryonic development are established maternally. Vasa, a DEAD-box RNA helicase, accumulates in the posterior pole plasm, where it is required for embryonic germ cell specification. Maintenance of Vasa at the posterior pole requires the deubiquitinating enzyme Fat facets, which protects Vasa from degradation. Here, we found that Gustavus (Gus) and Fsn, two ubiquitin Cullin-RING E3 ligase specificity receptors, bind to the same motif on Vasa through their paralogous B30.2/SPRY domains. Both Gus and Fsn accumulate in the pole plasm in a Vasa-dependent manner. Posterior Vasa accumulation is precocious in Fsn mutant oocytes; Fsn overexpression reduces ovarian Vasa levels, and embryos from Fsn-overexpressing females form fewer primordial germ cells (PGCs); thus, Fsn destabilizes Vasa. In contrast, endogenous Gus may promote Vasa activity in the pole plasm, as gus females produce embryos with fewer PGCs, and posterior accumulation of Vas is delayed in gus mutant oocytes that also lack one copy of cullin-5. We propose that Fsn- and Gus-containing E3 ligase complexes contribute to establishing a fine-tuned steady state of Vasa ubiquitination that influences the kinetics of posterior Vasa deployment.

AB - In Drosophila species, molecular asymmetries guiding embryonic development are established maternally. Vasa, a DEAD-box RNA helicase, accumulates in the posterior pole plasm, where it is required for embryonic germ cell specification. Maintenance of Vasa at the posterior pole requires the deubiquitinating enzyme Fat facets, which protects Vasa from degradation. Here, we found that Gustavus (Gus) and Fsn, two ubiquitin Cullin-RING E3 ligase specificity receptors, bind to the same motif on Vasa through their paralogous B30.2/SPRY domains. Both Gus and Fsn accumulate in the pole plasm in a Vasa-dependent manner. Posterior Vasa accumulation is precocious in Fsn mutant oocytes; Fsn overexpression reduces ovarian Vasa levels, and embryos from Fsn-overexpressing females form fewer primordial germ cells (PGCs); thus, Fsn destabilizes Vasa. In contrast, endogenous Gus may promote Vasa activity in the pole plasm, as gus females produce embryos with fewer PGCs, and posterior accumulation of Vas is delayed in gus mutant oocytes that also lack one copy of cullin-5. We propose that Fsn- and Gus-containing E3 ligase complexes contribute to establishing a fine-tuned steady state of Vasa ubiquitination that influences the kinetics of posterior Vasa deployment.

KW - Amino Acid Sequence

KW - Animals

KW - Animals, Genetically Modified

KW - Carrier Proteins

KW - Cullin Proteins

KW - DEAD-box RNA Helicases

KW - Drosophila Proteins

KW - Drosophila melanogaster

KW - F-Box Proteins

KW - Female

KW - Male

KW - Models, Molecular

KW - Molecular Sequence Data

KW - Ovary

KW - Protein Conformation

KW - Receptors, Cytoplasmic and Nuclear

KW - Recombinant Fusion Proteins

KW - Sequence Alignment

KW - Signal Transduction

KW - Ubiquitin-Protein Ligases

U2 - 10.1128/MCB.01100-09

DO - 10.1128/MCB.01100-09

M3 - Journal article

C2 - 20123973

SN - 0270-7306

VL - 30

SP - 1769

EP - 1782

JO - Molecular and Cellular Biology

JF - Molecular and Cellular Biology

IS - 7

ER -