Limits...
An anillin homologue, Mid2p, acts during fission yeast cytokinesis to organize the septin ring and promote cell separation.

Tasto JJ, Morrell JL, Gould KL - J. Cell Biol. (2003)

Bottom Line: Simanis. 1996.Mid2p colocalizes with septins, and mid2 Delta cells display disorganized, diffuse septin rings and a cell separation defect similar to septin deletion strains. mid2 gene expression and protein levels fluctuate during the cell cycle in a sep1- and Skp1/Cdc53/F-box (SCF)-dependent manner, respectively, implying that Mid2p activity must be carefully regulated.Overproduction of Mid2p depolarizes cell growth and affects the organization of both the septin and actin cytoskeletons.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.

ABSTRACT
Anillin is a conserved protein required for cell division (Field, C.M., and B.M. Alberts. 1995. J. Cell Biol. 131:165-178; Oegema, K., M.S. Savoian, T.J. Mitchison, and C.M. Field. 2000. J. Cell Biol. 150:539-552). One fission yeast homologue of anillin, Mid1p, is necessary for the proper placement of the division site within the cell (Chang, F., A. Woollard, and P. Nurse. 1996. J. Cell Sci. 109(Pt 1):131-142; Sohrmann, M., C. Fankhauser, C. Brodbeck, and V. Simanis. 1996. Genes Dev. 10:2707-2719). Here, we identify and characterize a second fission yeast anillin homologue, Mid2p, which is not orthologous with Mid1p. Mid2p localizes as a single ring in the middle of the cell after anaphase in a septin- and actin-dependent manner and splits into two rings during septation. Mid2p colocalizes with septins, and mid2 Delta cells display disorganized, diffuse septin rings and a cell separation defect similar to septin deletion strains. mid2 gene expression and protein levels fluctuate during the cell cycle in a sep1- and Skp1/Cdc53/F-box (SCF)-dependent manner, respectively, implying that Mid2p activity must be carefully regulated. Overproduction of Mid2p depolarizes cell growth and affects the organization of both the septin and actin cytoskeletons. In the presence of a nondegradable Mid2p fragment, the septin ring is stabilized and cell cycle progression is delayed. These results suggest that Mid2p influences septin ring organization at the site of cell division and its turnover might normally be required to permit septin ring disassembly.

Show MeSH

Related in: MedlinePlus

Mid2p is an S. pombe anillin homologue. (A) Alignment of human anillin with S. pombe Mid1p and Mid2p. Identical amino acids are in solid boxes and similar residues are shaded. The PH domain is underlined. (B) mid2 is not essential. Wild type (KGY246), mid1Δ (KGY2955), mid2Δ (KGY3135), and mid1Δ mid2Δ (KGY3125) cells were grown at 25°C and stained with Hoechst 33258 and aniline blue. Bar, 5 μm.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2172762&req=5

fig1: Mid2p is an S. pombe anillin homologue. (A) Alignment of human anillin with S. pombe Mid1p and Mid2p. Identical amino acids are in solid boxes and similar residues are shaded. The PH domain is underlined. (B) mid2 is not essential. Wild type (KGY246), mid1Δ (KGY2955), mid2Δ (KGY3135), and mid1Δ mid2Δ (KGY3125) cells were grown at 25°C and stained with Hoechst 33258 and aniline blue. Bar, 5 μm.

Mentions: Examination of the S. pombe protein database identified an uncharacterized protein with homology to Mid1p that has been termed Mid2p (Q9P7Y8) (Fig. 1 A). Mid2p has a predicted molecular mass of 78.7 kD. The overall similarity between Mid2p and either Mid1p or Hs anillin is 24.3% and 19.5%, respectively. Mid2p also shares moderate sequence similarity with two other fungal proteins, S. cerevisiae Bud4p (14.9%; Sanders and Herskowitz, 1996) and Candida albicans Int1p (12.8%; Gale et al., 1996). All of these proteins possess a carboxy-terminal pleckstrin homology (PH)* domain while Mid2p has the shortest amino terminus (Fig. 1 A) (Lemmon and Ferguson, 2001).


An anillin homologue, Mid2p, acts during fission yeast cytokinesis to organize the septin ring and promote cell separation.

Tasto JJ, Morrell JL, Gould KL - J. Cell Biol. (2003)

Mid2p is an S. pombe anillin homologue. (A) Alignment of human anillin with S. pombe Mid1p and Mid2p. Identical amino acids are in solid boxes and similar residues are shaded. The PH domain is underlined. (B) mid2 is not essential. Wild type (KGY246), mid1Δ (KGY2955), mid2Δ (KGY3135), and mid1Δ mid2Δ (KGY3125) cells were grown at 25°C and stained with Hoechst 33258 and aniline blue. Bar, 5 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2172762&req=5

fig1: Mid2p is an S. pombe anillin homologue. (A) Alignment of human anillin with S. pombe Mid1p and Mid2p. Identical amino acids are in solid boxes and similar residues are shaded. The PH domain is underlined. (B) mid2 is not essential. Wild type (KGY246), mid1Δ (KGY2955), mid2Δ (KGY3135), and mid1Δ mid2Δ (KGY3125) cells were grown at 25°C and stained with Hoechst 33258 and aniline blue. Bar, 5 μm.
Mentions: Examination of the S. pombe protein database identified an uncharacterized protein with homology to Mid1p that has been termed Mid2p (Q9P7Y8) (Fig. 1 A). Mid2p has a predicted molecular mass of 78.7 kD. The overall similarity between Mid2p and either Mid1p or Hs anillin is 24.3% and 19.5%, respectively. Mid2p also shares moderate sequence similarity with two other fungal proteins, S. cerevisiae Bud4p (14.9%; Sanders and Herskowitz, 1996) and Candida albicans Int1p (12.8%; Gale et al., 1996). All of these proteins possess a carboxy-terminal pleckstrin homology (PH)* domain while Mid2p has the shortest amino terminus (Fig. 1 A) (Lemmon and Ferguson, 2001).

Bottom Line: Simanis. 1996.Mid2p colocalizes with septins, and mid2 Delta cells display disorganized, diffuse septin rings and a cell separation defect similar to septin deletion strains. mid2 gene expression and protein levels fluctuate during the cell cycle in a sep1- and Skp1/Cdc53/F-box (SCF)-dependent manner, respectively, implying that Mid2p activity must be carefully regulated.Overproduction of Mid2p depolarizes cell growth and affects the organization of both the septin and actin cytoskeletons.

View Article: PubMed Central - PubMed

Affiliation: Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.

ABSTRACT
Anillin is a conserved protein required for cell division (Field, C.M., and B.M. Alberts. 1995. J. Cell Biol. 131:165-178; Oegema, K., M.S. Savoian, T.J. Mitchison, and C.M. Field. 2000. J. Cell Biol. 150:539-552). One fission yeast homologue of anillin, Mid1p, is necessary for the proper placement of the division site within the cell (Chang, F., A. Woollard, and P. Nurse. 1996. J. Cell Sci. 109(Pt 1):131-142; Sohrmann, M., C. Fankhauser, C. Brodbeck, and V. Simanis. 1996. Genes Dev. 10:2707-2719). Here, we identify and characterize a second fission yeast anillin homologue, Mid2p, which is not orthologous with Mid1p. Mid2p localizes as a single ring in the middle of the cell after anaphase in a septin- and actin-dependent manner and splits into two rings during septation. Mid2p colocalizes with septins, and mid2 Delta cells display disorganized, diffuse septin rings and a cell separation defect similar to septin deletion strains. mid2 gene expression and protein levels fluctuate during the cell cycle in a sep1- and Skp1/Cdc53/F-box (SCF)-dependent manner, respectively, implying that Mid2p activity must be carefully regulated. Overproduction of Mid2p depolarizes cell growth and affects the organization of both the septin and actin cytoskeletons. In the presence of a nondegradable Mid2p fragment, the septin ring is stabilized and cell cycle progression is delayed. These results suggest that Mid2p influences septin ring organization at the site of cell division and its turnover might normally be required to permit septin ring disassembly.

Show MeSH
Related in: MedlinePlus