• Media type: E-Article
  • Title: A small cysteine-rich extracellular protein, VCRP, is inducible by the sex-inducer of Volvox carteri and by wounding
  • Contributor: Hallmann, Armin
  • Published: Springer-Verlag, 2007
  • Published in: Planta, 226 (2007) 3, Seite 719-727
  • Language: English
  • ISSN: 0032-0935; 1432-2048
  • Origination:
  • Footnote:
  • Description: <p>The green alga Volvox carteri represents one of the simplest multicellular organisms: it is composed of only two cell types, somatic and reproductive. Volvox is capable of both vegetative and sexual reproduction. Sexual development of males and females is triggered by a sex-inducer at concentrations as low as 10-16 M. By differential screenings of cDNA libraries, a novel gene was identified that is under the control of this sex-inducer and that encodes a small cysteine-rich extracellular protein, named VCRP. Analysis of the VCRP polypeptide sequence suggests ten disulfide bonds and a dimetal-binding capacity. VCRP mRNA is detectable in males and females ∼1 h after the spheroids' first contact with the sex-inducer, but transcription is restricted to the somatic cell-type. mRNA and protein synthesis is triggered not only by the sex-inducer, but also by wounding. VCRP does not share significant sequence similarity with any known protein sequence, but a potential EGF-like calcium-binding motif and a potential plant metallothionein family-15 motif have been identified. The characteristics of VCRP suggest a function as a signal transducer molecule, an extracellular second messenger from somatic cells to reproductive cells, or a role within the stress response.</p>