Whi3 binds the mRNA of the G1 cyclin CLN3 to modulate cell fate in budding yeast.
Eukaryotic cells commit in G1 to a new mitotic cycle or to diverse differentiation processes. Here we show that Whi3 is a negative regulator of Cln3, a G1 cyclin that promotes transcription of many genes to trigger the G1/S transition in budding yeast. Whi3 contains an RNA-recognition motif that specifically binds the CLN3 mRNA, with no obvious effects on Cln3 levels, and localizes the CLN3 mRNA into discrete cytoplasmic foci. This is the first indication that G1 events may be regulated by locally restricting the synthesis of a cyclin. Moreover, Whi3 is also required for restraining Cln3 function in meiosis, filamentation, and mating, thus playing a key role in cell fate determination in budding yeast.
Garí
E
E
Departament de Ciències Mèdiques Bàsiques, Universitat de Lleida, 25198 Lleida, Catalunya, Spain.
Volpe
T
T
Wang
H
H
Gallego
C
C
Futcher
B
B
Aldea
M
M
D020816:Amino Acid Motifs; D015152:Blotting, Northern; D019070:Cell Lineage; D056746:Cyclin G; D016213:Cyclins / Q000737:chemistry* / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism*; D017404:In Situ Hybridization, Fluorescence; D008540:Meiosis; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism* / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins; D004718:Saccharomycetales / Q000502:physiology*; D013997:Time Factors
C079895:CLN3 protein, S cerevisiae; D056746:Cyclin G; D016213:Cyclins; D005656:Fungal Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C440012:Whi3 protein, S cerevisiae; D012313:RNA