Control of cell division by a retinoblastoma protein homolog in Chlamydomonas

J. G. Umen, U. W. Goodenough

Research output: Contribution to journalArticlepeer-review

183 Scopus citations

Abstract

A key pathway that controls both cell division and differentiation in animal cells is mediated by the retinoblastoma (RB) family of tumor suppressors, which gate the passage of cells from G1 to S and through S phase. The role(s) of the RB pathway in plants are not yet clearly defined, nor has there been any evidence for its presence in unicellular organisms. Here we have identified an RB homolog encoded by the mat3 gene in Chlamydomonas reinhardtii, a unicellular green alga in the land plant lineage. Chlamydomonas cells normally grow to many times their original size during a prolonged G1 and then undergo multiple alternating rounds of S phase and mitosis to produce daughter cells of uniform size. mat3 mutants produce small daughter cells and show defects in two size-dependent cell cycle controls: They initiate the cell cycle at a below-normal size, and they undergo extra rounds of S phase/mitosis. Unlike mammalian RB mutants, mat3 mutants do not have a shortened G1, do not enter S phase prematurely, and can exit the cell cycle and differentiate normally, indicating that the RB pathway in Chlamydomonas has a different role than in animals.

Original languageEnglish
Pages (from-to)1652-1661
Number of pages10
JournalGenes and Development
Volume15
Issue number13
DOIs
StatePublished - Jul 1 2001

Keywords

  • Cell cycle
  • Cell size
  • Mat3
  • Plant
  • RB

Fingerprint

Dive into the research topics of 'Control of cell division by a retinoblastoma protein homolog in Chlamydomonas'. Together they form a unique fingerprint.

Cite this