Phosphorylation of sea urchin sperm H1 and H2B histones precedes chromatin decondensation and H1 exchange during pronuclear formation

Green, G.R.; Poccia, Dominic

doi:10.1016/0012-1606(85)90026-0

Cited by 108 publications

(75 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Sperm histones SpH1 and SpH2B are phosphorylated in vivo within 3 min of fertilization (43), as well as in vitro, albeit at a slower rate (29). Interestingly, the conversion of Sp histones to their modified form in vivo takes place in eggs treated with DMAP, indicating that the sperm histone kinase is DMAPinsensitive (41).…”

Section: Pkc-mediated Interphase Laminmentioning

confidence: 96%

Protein Kinase C-mediated Interphase Lamin B Phosphorylation and Solubilization

Collas¹,

Thompson²,

Fields³

et al. 1997

Journal of Biological Chemistry

View full text Add to dashboard Cite

Disassembly of the sperm nuclear envelope at fertilization is one of the earliest events in the development of the male pronucleus. We report that nuclear lamina disassembly in interphase sea urchin egg cytosol is a result of lamin B phosphorylation mediated by protein kinase C (PKC). Lamin B of permeabilized sea urchin sperm nuclei incubated in fertilized egg G 1 phase cytosolic extract is phosphorylated within 1 min of incubation and solubilized prior to sperm chromatin decondensation. Phosphorylation is Ca 2؉ -dependent. It is reversibly inhibited by the PKC-specific inhibitor chelerythrine, a PKC pseudosubstrate inhibitor peptide, and a PKC substrate peptide, but not by inhibitors of PKA, p34 cdc2 or calmodulin kinase II. Phosphorylation is inhibited by immunodepletion of cytosolic PKC and restored by addition of purified rat brain PKC. Sperm lamin B is a substrate for rat brain PKC in vitro, resulting in lamin B solubilization. Two-dimensional phosphopeptide maps of lamin B phosphorylated by the cytosolic kinase and by purified rat PKC are virtually identical. These data suggest that PKC is the major kinase required for interphase disassembly of the sperm lamina.The nuclear lamina consists of a polymeric network of intermediate filament molecules, the nuclear lamins, underlying the inner nuclear membrane. The lamina is a dynamic structure, undergoing expansion during interphase of the cell cycle, and depolymerization at mitosis upon breakdown of the nuclear envelope (NE) 1 (1). Mitotic disassembly and reassembly of the lamina is regulated by reversible lamin phosphorylation and dephosphorylation (1). Interphase lamin phosphorylation has also been reported (2-6), but its significance is not fully understood.Several lamin kinases have been identified that promote mitotic lamina solubilization or inhibit lamina assembly in vitro. They include cyclin B/p34 cdc2 (7), S6 kinase II (8), protein kinase C (PKC) (4, 9), and the cAMP-dependent protein kinase PKA (10). Down-regulation of PKA has also been shown to be essential for mitotic lamina disassembly (11). Although not a lamin kinase, Ca 2ϩ /calmodulin-dependent kinase II (CaM kinase II) is also involved in mitotic NE breakdown in sea urchin embryos (12). PKC has also been shown to phosphorylate chicken lamin B 2 in interphase, a process thought to regulate lamin import into the nucleus (13). These observations imply that multiple kinases regulate the dynamics of the nuclear lamina during the cell cycle. The transformation of the sea urchin sperm nucleus into a pronucleus at fertilization provides an opportunity to investigate NE assembly/disassembly during interphase. Sea urchin eggs are fertilized in G 1 phase of the first cell cycle after completion of both meiotic divisions. At fertilization, the sperm NE vesiculates and a new NE reforms around the male pronucleus as the sperm chromatin decondenses (14). Male pronuclear formation has been duplicated in a cell-free system by incubating detergent-permeabilized sperm nuclei in fertilized egg extracts (15)(16)(1...

show abstract

Section: Pkc-mediated Interphase Laminmentioning

confidence: 96%

Protein Kinase C-mediated Interphase Lamin B Phosphorylation and Solubilization

Collas¹,

Thompson²,

Fields³

et al. 1997

Journal of Biological Chemistry

View full text Add to dashboard Cite

show abstract

“…In sea urchins, a maternal kinase phosphorylates sperm-specific histones. This is thought to weaken the sperm histones' attachment to sperm DNA, causing chromatin relaxation (Green and Poccia, 1985;reviewed in Green, 2001). A candidate for the maternal kinase is Cdk2, because it colocalizes with the male pronucleus after fertilization (Schnackenberg and Marzluff, 2002;reviewed in Imschenetzky et al, 2003).…”

Section: Conversion Of the Sperm Nucleus Into A Male Pronucleusmentioning

confidence: 99%

Transitioning from egg to embryo: Triggers and mechanisms of egg activation

Horner

Wolfner

2008

Developmental Dynamics

183

177

View full text Add to dashboard Cite

The transition from mature oocyte to developing embryo requires a coordinated series of events, collectively known as egg activation. Egg activation includes changes to egg coverings to prevent polyspermy, release of oocyte meiotic arrest, generation of haploid female and male pronuclei, changes in maternal mRNAs and protein populations, and cytoskeletal rearrangements. In many animals, egg activation is triggered by fertilization, which increases intracellular calcium within the oocyte and thereby regulates molecular events of egg activation. In other animals, fertilization-independent external signals, including mechanical stimulation of eggs and/or changes in ionic milieu, trigger activation. Recent studies have clarified the upstream portion of pathways leading to eggshell changes and cell cycle resumption and have identified activation-induced changes in maternal mRNA and protein profiles that can identify molecular players in the downstream events of egg activation. We review signals that trigger activation and how they link to subsequent molecular events of egg activation. Developmental Dynamics 237:527-544, 2008.

show abstract

“…Phosphorylation sites are typically located within variant DNA-binding regions of sperm and oocyte histones, indicating that their special functions are realised through the charge-altering effects of reversible histone phosphorylation (Norbury & Nurse, 1992). These indicate that histone kinases and phosphatases participate in the control of chromatin structure by altering histone-DNA interactions (Green & Piccia, 1985. Upon entering the oocyte cytoplasm at fertilisation, the sperm nucleus undergoes a dramatic morphological transformation as the male pronucleus is formed.…”

Section: Introductionmentioning

confidence: 99%

Reversible changes in protein phosphorylation during germinal vesicle breakdown and pronuclear formation in bovine oocytes in vitro

Chian

Chung²,

Niwa³

et al. 2003

Zygote

View full text Add to dashboard Cite

This study examined the event of protein phosphorylation in bovine oocytes during germinal vesicle breakdown (GVBD) and formation of pronuclei following fertilisation in vitro. Immature oocytes were obtained from abattoir materials and cultured in vitro. The oocytes were labelled with [32P]orthophosphate at 3 h intervals from 0 to 12 h following maturation in culture or from 3 to 18 h following insemination. One-dimensional gel electrophoresis indicated that levels of protein phosphorylation are low prior to GVBD. However, the levels of protein phosphorylation at approximately 40 kDa, 27 kDa, 23 kDa and 18 kDa increased substantially following GVBD and then decreased gradually as maturation in culture progressed. In contrast, the levels of protein phosphorylation increased gradually in the oocytes following pronucleus formation. Further, two-dimensional gel electrophoresis indicated that the protein at approximately 18 kDa reversibly changed in the oocytes during maturation and fertilisation. These results indicate that the reversible changes of this phosphoprotein may be related to either cell cycle transition or pronucleus formation during maturation and fertilisation in bovine oocytes

show abstract

Phosphorylation of sea urchin sperm H1 and H2B histones precedes chromatin decondensation and H1 exchange during pronuclear formation

Cited by 108 publications

References 60 publications

Protein Kinase C-mediated Interphase Lamin B Phosphorylation and Solubilization

Protein Kinase C-mediated Interphase Lamin B Phosphorylation and Solubilization

Transitioning from egg to embryo: Triggers and mechanisms of egg activation

Reversible changes in protein phosphorylation during germinal vesicle breakdown and pronuclear formation in bovine oocytes in vitro

Contact Info

Product

Resources

About