Cdc28-Clb mitotic kinase negatively regulates bud site assembly in the budding yeast.

نویسندگان

  • C G Padmashree
  • U Surana
چکیده

In the budding yeast Saccharomyces cerevisiae, a prospective mother normally commences the formation of a daughter (the bud) only in the G(1) phase of the cell division cycle. This suggests a strict temporal regulation of the processes that initiate the formation of a new bud. Using cortical localization of bud site components Spa2 and Bni1 as an indicator of bud site assembly, we show that cells assemble a bud site following inactivation of the Cdc28-Clb mitotic kinase but prior to START. Interestingly, an untimely inactivation of the mitotic kinase is sufficient to drive cells to assemble a new bud site inappropriately in G(2) or M phases. The induction of Cdc28/Clb kinase activity in G(1), on the other hand, dramatically reduces a cell's ability to construct an incipient bud site. Our findings strongly suggest that the Cdc28-Clb kinase plays a critical role in the mechanism that restricts the timing of bud formation to the G(1) phase of the cell cycle.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

B-Cyclin/CDKs Regulate Mitotic Spindle Assembly by Phosphorylating Kinesins-5 in Budding Yeast

Although it has been known for many years that B-cyclin/CDK complexes regulate the assembly of the mitotic spindle and entry into mitosis, the full complement of relevant CDK targets has not been identified. It has previously been shown in a variety of model systems that B-type cyclin/CDK complexes, kinesin-5 motors, and the SCF(Cdc4) ubiquitin ligase are required for the separation of spindle ...

متن کامل

A cell cycle checkpoint monitors cell morphogenesis in budding yeast

Checkpoint controls are regulatory pathways that inhibit cell cycle progression in cells that have not faithfully completed a prior step in the cell cycle. In the budding yeast Saccharomyces cerevisiae, DNA replication and spindle assembly are monitored by checkpoint controls that prevent nuclear division in cells that have failed to complete these processes. During the normal cell cycle, bud f...

متن کامل

Morphogenesis in the yeast cell cycle: regulation by Cdc28 and cyclins

Analysis of cell cycle regulation in the budding yeast Saccharomyces cerevisiae has shown that a central regulatory protein kinase, Cdc28, undergoes changes in activity through the cell cycle by associating with distinct groups of cyclins that accumulate at different times. The various cyclin/Cdc28 complexes control different aspects of cell cycle progression, including the commitment step know...

متن کامل

Regulation of B-type cyclin proteolysis by Cdc28-associated kinases in budding yeast.

In budding yeast, stability of the mitotic B-type cyclin Clb2 is tightly cell cycle-regulated. B-type cyclin proteolysis is initiated during anaphase and persists throughout the G1 phase. Cln-Cdc28 kinase activity at START is required to repress B-type cyclin-specific proteolysis. Here, we show that Clb-dependent kinases, when expressed during G1, are also capable of repressing the B-type cycli...

متن کامل

Coordinated Spindle Assembly and Orientation Requires Clb5p-Dependent Kinase in Budding Yeast

The orientation of the mitotic spindle along a polarity axis is critical in asymmetric cell divisions. In the budding yeast, Saccharomyces cerevisiae, loss of the S-phase B-type cyclin Clb5p under conditions of limited cyclin-dependent kinase activity (cdc28-4 clb5Delta cells) causes a spindle positioning defect that results in an undivided nucleus entering the bud. Based on time-lapse digital ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Journal of cell science

دوره 114 Pt 1  شماره 

صفحات  -

تاریخ انتشار 2001