HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Sperm Activate Eggs with a "PAWP"

Several hypotheses have been proposed to account for the biochemical and physiological mechanisms by which spermatozoa trigger zygotic development during mammalian fertilization. The currently favored model postulates that upon sperm-oocyte fusion, sperm-borne factors are released into the egg cytoplasm. These factors activate the dormant egg by eliciting intracellular Ca²⁺ oscillations, which serve as a secondary messenger for downstream effectors of zygotic development. Thus far, two sperm molecules, truncated c-Kit tyrosine kinase (tr-kit) and phospholipase C (PLC), have been shown to trigger oocyte activation.

PAWP is localized to the postacrosomal sheath in sperm.

This new study by Alexander T. H. Wu and colleagues reports the discovery of another sperm-borne protein that induces formation of pronuclei in eggs. Wu et al. named the protein PAWP for postacrosomal sheath WW domain binding protein. This makes PAWP, at the very least, a new sperm-borne factor that activates a downstream event of egg activation. In the discussion, the authors speculate that PAWP may also act further upstream in this process. Thus, PAWP triggers at least one important event of egg activation, and there is a good chance that it could prove to be the primary initiator of zygotic development.

FOOTNOTES

See referenced article, J. Biol. Chem. 2007, 282, 12164-12175

[More Papers of the Week]