Cdc15 integrates Tem1 GTPase-mediated
spatial signals with Polo kinase-mediated
temporal cues to activate mitotic exit
Jeremy M. Rock and Angelika Amon1
David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts
02139, USA; Howard Hughes Medical Institute, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
In budding yeast, a Ras-like GTPase signaling cascade known as the mitotic exit network (MEN) promotes exit
from mitosis. To ensure the accurate execution of mitosis, MEN activity is coordinated with other cellular
events and restricted to anaphase. The MEN GTPase Tem1 has been assumed to be the central switch in MEN
regulation. We show here that during an unperturbed cell cycle, restricting MEN activity to anaphase can occur
in a Tem1 GTPase-independent manner. We found that the anaphase-specific activation of the MEN in the
absence of Tem1 is controlled by the Polo kinase Cdc5. We further show that both Tem1 and Cdc5 are required to
recruit the MEN kinase Cdc15 to spindle pole bodies, which is both necessary and sufficient to induce MEN
signaling. Thus, Cdc15 functions as a coincidence detector of two essential cell cycle oscillators: the Polo kinase
Cdc5 synthesis/degradation cycle and the Tem1 G-protein cycle. The Cdc15-dependent integration of these
temporal (Cdc5 and Tem1 activity) and spatial (Tem1 activity) signals ensures that exit from mitosis occurs only
after proper genome partitioning.
[Keywords: Cdc14; Cdc15; Cdc5; mitotic exit network; NDR kinase; Polo kinase; Tem1]
Supplemental material is available for this article.
Received June 17, 2011; revised version accepted August 12, 2011.
The creation of a daughter cell requires the faithful du-
plication and segregation of the genome. The success of
this process necessitates the temporal and spatial co-
ordination of genome segregation with the final cell cycle
transition, exit from mitosis, when the mitotic spindle is
disassembled, nuclei are reformed, and cytokinesis splits
the cell into two. In the absence of such coordination,
significant genetic and epigenetic changes occur. Thus, as
might be expected, the inability to coordinate genome
segregation with exit from mitosis is strongly associated
with cancer (Kops et al. 2005; Gonzalez 2007).
In budding yeast, exit from mitosis is controlled by the
essential protein phosphatase Cdc14. Cdc14 antagonizes
mitotic cyclin-dependent kinases (Clb-CDKs), the inacti-
et al. 1998; Visintin et al. 1998; Zachariae et al. 1998).
Cdc14 activity is tightly regulated. In cell cycle stages
prior to anaphase, Cdc14 is sequestered within the nu-
cleolus as a result of its association with its nucleolar-
localized inhibitor, Cfi1/Net1 (Shou et al. 1999; Visintin
et al. 1999). Upon anaphase entry, Cdc14 is released from
the nucleolus and spreads throughout the nucleus and, to
a significantly lesser extent, the cytoplasm. This early
anaphase release of Cdc14 is mediated by the FEAR
network and results in a pulse of Cdc14 activity (Pereira
et al. 2002; Stegmeier et al. 2002; Yoshida et al. 2002).
While not essential, FEAR network-mediated release of
Cdc14 from the nucleolus is crucial for the accurate
execution of anaphase (Rock and Amon 2009). Cdc14
release from the nucleolus during late anaphase is pro-
moted by the mitotic exit network (MEN), which drives
the sustained release of Cdc14 in both the nucleus and
the cytoplasm and results in exit from mitosis (Stegmeier
and Amon 2004).
The MEN is a Ras-like GTPase signal transduction
cascade (see Figure 7B, below, for a pathway diagram;
for review, see Stegmeier and Amon 2004). As in other
G-protein signaling pathways, the GTPase Tem1 is
thought to be the central switch regulating MEN activity
(Cooper and Nelson 2006; Wang and Ng 2006; Geymonat
et al. 2009; Chan and Amon 2010). Tem1 is negatively
regulated by its two-component GTPase-activating pro-
tein (GAP), Bub2–Bfa1. The Bub2–Bfa1 complex is regu-
lated by two protein kinases. The Polo kinase Cdc5
phosphorylates Bfa1, which reduces Bub2–Bfa1 GAP
activity. The protein kinase Kin4 functions in opposition
to Cdc5, phosphorylating Bfa1 and thus rendering the
GAP insensitive to Cdc5-dependent inhibitory phosphor-
Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.17257711.
GENES & DEVELOPMENT 25:1943–1954 ? 2011 by Cold Spring Harbor Laboratory Press ISSN 0890-9369/11; www.genesdev.org1943
ylation (Maekawa et al. 2007). Tem1 is positively regu-
lated by Lte1, which inhibits Kin4 in the bud (Bertazzi
et al. 2011; Falk et al. 2011).
During late anaphase, Tem1-GTP is thought to bind to
and activate the protein kinase Cdc15, which then
activates the downstream kinase Dbf2 associated with
its activating subunit, Mob1. Based on binding data and
homology with known scaffolds, Nud1 is thought to
function as a scaffold for the core MEN components
Tem1, Bub2–Bfa1, Cdc15, and Dbf2-Mob1 at spindle pole
bodies (SPBs) (Gruneberg et al. 2000; Valerio-Santiago and
Monje-Casas 2011). Tem1 SPB localization is essential for
MEN activation, and it is thought that SPB localization of
Cdc15, Dbf2, and Mob1 is also essential (Valerio-Santiago
and Monje-Casas 2011). Activation of Dbf2-Mob1 results,
at least in part, in the phosphorylation of Cdc14’s nuclear
localization sequence and causes the retention of Cdc14
in the cytoplasm, where it can act on its substrates
(Mohl et al. 2009). Activation of the MEN in late ana-
phase is essential for the sustained release of Cdc14
from the nucleolus, which ultimately promotes exit from
The mechanisms by which MEN activity and exit from
mitosis are temporally and spatially coordinated with
genome segregation are beginning to be understood. MEN
activity is controlled by spindle position. When the ana-
phase spindle is not correctly aligned along the mother–
daughter cell axis, MEN signaling is inhibited (Yeh et al.
1995). This spindle position control of MEN signaling is
accomplished by a system composed of a MEN inhibitory
and a MEN-activating zone and a sensor that moves
between them. The MEN inhibitor Kin4 is located in
the mother cell, the MEN activator Lte1 is located in the
bud, and the MEN GTPase Tem1 is localized to the SPB
(Bardin et al. 2000; Pereira et al. 2000; D’Aquino et al.
2005; Maekawa et al. 2007). Only when the MEN-bearing
SPB escapes the MEN inhibitor Kin4 in the mother cell
and moves into the bud where the MEN activator Lte1
resides can exit from mitosis occur. In this manner,
spatial information is sensed and translated to regulate
Spindle position cannot be the only event controlling
MEN activity, as exit from mitosis occurs at the appro-
priate time in lte1D or kin4D cells with correctly posi-
tioned spindles. Here, we describe the identification of
a novel role for Cdc5 in regulating the timing of MEN
activation. Interestingly, this essential Cdc5-dependent
MEN-activating signal does not regulate the GTPase
Tem1, but rather the Tem1 effector Cdc15. We found
that Cdc5 is essential for the anaphase-specific recruit-
ment of Cdc15 to SPBs. Furthermore, the artificial
targeting of Cdc15 to the SPB bypasses the requirement
for both Tem1 and Cdc5 in MEN activation. Our results
indicate that multiple signals converge on the MEN
effector kinase Cdc15 to integrate spatial (spindle po-
sition) and temporal (Cdc5 activation) cues with mi-
totic exit. Thus, Cdc15 functions as a coincidence de-
tector, integrating spatial and temporal signals to ensure
that exit from mitosis only occurs after proper genome
LTE1 and KIN4-independent activation of the MEN
LTE1 and KIN4 are the central mediators of MEN
regulation by spindle position (Bardin et al. 2000; Pereira
et al. 2000; Castillon et al. 2003; D’Aquino et al. 2005;
Pereira and Schiebel 2005; Geymonat et al. 2009; Bertazzi
et al. 2011; Falk et al. 2011). The subcellular partitioning
of these two proteins ensures that cells that have a mis-
positioned anaphase spindle do not prematurely activate
the MEN. It is unclear, however, whether LTE1 and KIN4
are also important for regulating the proper timing of
MEN activation in cells where spindles are correctly
aligned along the mother–bud axis. To address this ques-
tion, we examined the consequences of deleting KIN4
and LTE1 on MEN activity. Cells were arrested in G1
using pheromone and then released to allow them to
progress through the cell cycle in a synchronous manner.
MEN activity was monitored by measuring the kinase
activity of the most downstream MEN kinase, Dbf2-
Mob1. Dbf2 kinase activity was restricted to anaphase
in wild-type cells (Fig. 1A,B; Toyn and Johnston 1994).
Similar results were obtained in lte1D kin4D cells (Fig.
1A,B). Thus, there must exist Kin4- and Lte1-independent
mechanisms that restrict MEN activity to anaphase in
cells with correctly positioned spindles.
Anaphase-specific activation of the MEN
in the absence of TEM1
Our data indicate that regulatory mechanisms other than
spindle position control MEN activity. To identify these
signals, we first asked whether, as in other GTPase
signaling cascades, all critical MEN regulation is medi-
ated by the GTPase Tem1. To this end, we measured Dbf2
kinase activity in cells lacking the essential MEN GTPase
Tem1 but kept alive by overexpression of CDC15 (hence-
forth tem1D CDC15-UP) (Pereira et al. 2000). Surprisingly,
growth of tem1D CDC15-UP cells was indistinguishable
from that of wild-type cells (Fig. 1C), and cell cycle pro-
gression occurred with near wild-type kinetics (Fig. 1D).
activity remained restricted to anaphase in tem1D CDC15-
Control of MEN activity by spindle position was,
however, lost in the tem1D CDC15-UP strain. Cells
lacking cytoplasmic dynein (dyn1D cells) frequently mis-
position their spindles at low temperature and arrest in
anaphase because the MEN GTPase Tem1 is inhibited by
Bub2–Bfa1 (for review, see Fraschini et al. 2008). When
the GAP is inactivated by deleting BUB2 or BFA1, cells
with mispositioned spindles will not arrest in anaphase,
but rather exit mitosis to produce anucleate and multi-
nucleate cells (Supplemental Fig. 1; Bardin et al. 2000;
Bloecher et al. 2000; Pereira et al. 2000). As in bub2D
cells, tem1D CDC15-UP cells did not arrest in anaphase
in response to spindle misposition (Supplemental Fig. 1).
Our data confirm that spindle position control of the
MEN is mediated by Tem1. Our data also indicate that
Rock and Amon
1944 GENES & DEVELOPMENT
using the PhosphorImaging system. Western blots were quanti-
fied using ECL Plus (GE Healthcare) and fluorescence imaging.
Indirect in situ immunofluorescence methods to detect Tub1
were performed as previously described (Kilmartin and Adams
1984). For imaging of Cdc15-eGFP and Cdc15-eGFP-Cnm67,
cells were fixed for 2 min in 4% paraformaldehyde (in 3.4%
sucrose solution). Cells were washed once in KPO4/sorbitol
(1.2 M sorbitol, 0.1 M KPO4 at pH 7.5) and resuspended in
KPO4/sorbitol supplemented with 1% Triton. Prior to imaging,
cells were stained with Prolong Gold anti-fade reagent (Invitro-
gen, P36935). Cells were imaged within 24 h on a Zeiss Axioplan
2 microscope and a Hamamatsu OCRA-ER digital camera.
Flow cytometric DNA quantitation was performed as described
by Haase and Reed (2002).
We thank Frank Solomon, Iain Cheeseman, Rosella Visintin,
and members of the Amon laboratory for comments on the
manuscript. This work was supported by the National Institutes
of Health (GM056800 to A.A.)and an NSF Predoctoral Fellowship
(to J.M.R.). A.A. is an investigator of the Howard Hughes Medical
Asakawa K, Yoshida S, Otake F, Toh-e A. 2001. A novel
functional domain of Cdc15 kinase is required for its in-
teraction with Tem1 GTPase in Saccharomyces cerevisiae.
Genetics 157: 1437–1450.
Bachmair A, Finley D, Varshavsky A. 1986. In vivo half-life of
a protein is a function of its amino-terminal residue. Science
Bardin AJ, Visintin R, Amon A. 2000. A mechanism for coupling
exit from mitosis to partitioning of the nucleus. Cell 102: 21–
Bardin AJ, Boselli MG, Amon A. 2003. Mitotic exit regulation
through distinct domains within the protein kinase Cdc15.
Mol Cell Biol 23: 5018–5030.
Bertazzi DT, Kurtulmus B, Pereira G. 2011. The cortical protein
Lte1 promotes mitotic exit by inhibiting the spindle position
checkpoint kinase Kin4. J Cell Biol 193: 1033–1048.
Bloecher A, Venturi GM, Tatchell K. 2000. Anaphase spindle
position is monitored by the BUB2 checkpoint. Nat Cell Biol
Bothos J, Tuttle RL, Ottey M, Luca FC, Halazonetis TD. 2005.
Human LATS1 is a mitotic exit network kinase. Cancer Res
Castillon GA, Adames NR, Rosello CH, Seidel HS, Longtine
MS, Cooper JA, Heil-Chapdelaine RA. 2003. Septins have
a dual role in controlling mitotic exit in budding yeast. Curr
Biol 13: 654–658.
Chan LY, Amon A. 2010. Spindle position is coordinated with
cell-cycle progression through establishment of mitotic
exit-activating and -inhibitory zones. Mol Cell 39: 444–
Charles JF, Jaspersen SL, Tinker-Kulberg RL, Hwang L, Szidon A,
Morgan DO. 1998. The Polo-related kinase Cdc5 activates
and is destroyed by the mitotic cyclin destruction machinery
in S. cerevisiae. Curr Biol 8: 497–507.
Cheng L, Hunke L, Hardy CF. 1998. Cell cycle regulation of the
Saccharomyces cerevisiae polo-like kinase cdc5p. Mol Cell
Biol 18: 7360–7370.
Cooper JA, Nelson SA. 2006. Checkpoint control of mitotic
exit—do budding yeast mind the GAP? J Cell Biol 172: 331–
D’Aquino KE, Monje-Casas F, Paulson J, Reiser V, Charles GM,
Lai L, Shokat KM, Amon A. 2005. The protein kinase Kin4
inhibits exit from mitosis in response to spindle position
defects. Mol Cell 19: 223–234.
Falk JE, Chan LY, Amon A. 2011. Lte1 promotes mitotic exit by
controlling the localization of the spindle position check-
point kinase Kin4. Proc Natl Acad Sci 108: 12584–12590.
Fraschini R, Venturetti M, Chiroli E, Piatti S. 2008. The spindle
position checkpoint: how to deal with spindle misalignment
during asymmetric cell division in budding yeast. Biochem
Soc Trans 36: 416–420.
Geymonat M, Spanos A, Walker PA, Johnston LH, Sedgwick SG.
2003. In vitro regulation of budding yeast Bfa1/Bub2 GAP
activity by Cdc5. J Biol Chem 278: 14591–14594.
Geymonat M, Spanos A, de Bettignies G, Sedgwick SG. 2009.
Lte1 contributes to Bfa1 localization rather than stimulating
nucleotide exchange by Tem1. J Cell Biol 187: 497–511.
Gonzalez C. 2007. Spindle orientation, asymmetric division and
tumour suppression in Drosophila stem cells. Nat Rev Genet
Gruneberg U, Campbell K, Simpson C, Grindlay J, Schiebel E.
2000. Nud1p links astral microtubule organization and the
control of exit from mitosis. EMBO J 19: 6475–6488.
Haase SB, Reed SI. 2002. Improved flow cytometric analysis of
the budding yeast cell cycle. Cell Cycle 1: 132–136.
Habedanck R, Stierhof YD, Wilkinson CJ, Nigg EA. 2005. The
Polo kinase Plk4 functions in centriole duplication. Nat Cell
Biol 7: 1140–1146.
Halder G, Johnson RL. 2011. Hippo signaling: growth control
and beyond. Development 138: 9–22.
Hergovich A, Lamla S, Nigg EA, Hemmings BA. 2007. Centro-
some-associated NDR kinase regulates centrosome duplica-
tion. Mol Cell 25: 625–634.
Hu F, Wang Y, Liu D, Li Y, Qin J, Elledge SJ. 2001. Regulation of
the Bub2/Bfa1 GAP complex by Cdc5 and cell cycle check-
points. Cell 107: 655–665.
Jaspersen SL, Morgan DO. 2000. Cdc14 activates cdc15 to
promote mitotic exit in budding yeast. Curr Biol 10: 615–
Jaspersen SL, Charles JF, Tinker-Kulberg RL, Morgan DO. 1998.
A late mitotic regulatory network controlling cyclin de-
struction in Saccharomyces cerevisiae. Mol Biol Cell 9:
Johnson ES, Bartel B, Seufert W, Varshavsky A. 1992. Ubiquitin
as a degradation signal. EMBO J 11: 497–505.
Keck JM, Jones MH, Wong CC, Binkley J, Chen D, Jaspersen SL,
Holinger EP, Xu T, Niepel M, Rout MP, et al. 2011. A cell
cycle phosphoproteome of the yeast centrosome. Science
Kilmartin JV, Adams AE. 1984. Structural rearrangements of
tubulin and actin during the cell cycle of the yeast Saccha-
romyces. J Cell Biol 98: 922–933.
Konig C, Maekawa H, Schiebel E. 2010. Mutual regulation of
cyclin-dependent kinase and the mitotic exit network. J Cell
Biol 188: 351–368.
Kops GJ, Weaver BA, Cleveland DW. 2005. On the road to
cancer: aneuploidy and the mitotic checkpoint. Nat Rev
Cancer 5: 773–785.
Cdc15 integrates Tem1 and Cdc5 signals
GENES & DEVELOPMENT 1953
Lee KS, Park JE, Asano S, Park CJ. 2005. Yeast polo-like kinases:
functionally conserved multitask mitotic regulators. Onco-
gene 24: 217–229.
Luca FC, Mody M, Kurischko C, Roof DM, Giddings TH, Winey
M. 2001. Saccharomyces cerevisiae Mob1p is required for
cytokinesis and mitotic exit. Mol Cell Biol 21: 6972–6983.
Maekawa H, Priest C, Lechner J, Pereira G, Schiebel E. 2007.
The yeast centrosome translates the positional information
of the anaphase spindle into a cell cycle signal. J Cell Biol
Manzoni R, Montani F, Visintin C, Caudron F, Ciliberto A,
Visintin R. 2010. Oscillations in Cdc14 release and seques-
tration reveal a circuit underlying mitotic exit. J Cell Biol
Mehta S, Gould KL. 2006. Identification of functional domains
within the septation initiation network kinase, Cdc7. J Biol
Chem 281: 9935–9941.
Mohl DA, Huddleston MJ, Collingwood TS, Annan RS,
Deshaies RJ. 2009. Dbf2-Mob1 drives relocalization of pro-
tein phosphatase Cdc14 to the cytoplasm during exit from
mitosis. J Cell Biol 184: 527–539.
Molk JN, Schuyler SC, Liu JY, Evans JG, Salmon ED, Pellman D,
Bloom K. 2004. The differential roles of budding yeast
Tem1p, Cdc15p, and Bub2p protein dynamics in mitotic
exit. Mol Biol Cell 15: 1519–1532.
Mulvihill DP, Petersen J, Ohkura H, Glover DM, Hagan IM.
1999. Plo1 kinase recruitment to the spindle pole body and
its role in cell division in Schizosaccharomyces pombe. Mol
Biol Cell 10: 2771–2785.
Musacchio A, Salmon ED. 2007. The spindle-assembly check-
point in space and time. Nat Rev Mol Cell Biol 8: 379–393.
Park CJ, Park JE, Karpova TS, Soung NK, Yu LR, Song S, Lee KH,
Xia X, Kang E, Dabanoglu I, et al. 2008. Requirement for the
budding yeast polo kinase Cdc5 in proper microtubule
growth and dynamics. Eukaryot Cell 7: 444–453.
Pereira G, Schiebel E. 2005. Kin4 kinase delays mitotic exit in
response to spindle alignment defects. Mol Cell 19: 209–221.
Pereira G, Hofken T, Grindlay J, Manson C, Schiebel E. 2000.
The Bub2p spindle checkpoint links nuclear migration with
mitotic exit. Mol Cell 6: 1–10.
Pereira G, Manson C, Grindlay J, Schiebel E. 2002. Regulation of
the Bfa1p–Bub2p complex at spindle pole bodies by the cell
cycle phosphatase Cdc14p. J Cell Biol 157: 367–379.
Rock JM, Amon A. 2009. The FEAR network. Curr Biol 19:
R1063–R1068. doi: 10.1016/j.cub.2009.10.002.
Rose MD, Misra LM, Vogel JP. 1989. KAR2, a karyogamy gene,
is the yeast homolog of the mammalian BiP/GRP78 gene.
Cell 57: 1211–1221.
Schmidt S, Sohrmann M, Hofmann K, Woollard A, Simanis V.
1997. The Spg1p GTPase is an essential, dosage-dependent
inducer of septum formation in Schizosaccharomyces
pombe. Genes Dev 11: 1519–1534.
Shirayama M, Zachariae W, Ciosk R, Nasmyth K. 1998. The
Polo-like kinase Cdc5p and the WD-repeat protein Cdc20p/
fizzy are regulators and substrates of the anaphase promoting
complex in Saccharomyces cerevisiae. EMBO J 17: 1336–
Shou W, Seol JH, Shevchenko A, Baskerville C, Moazed D, Chen
ZW, Jang J, Charbonneau H, Deshaies RJ. 1999. Exit from
mitosis is triggered by Tem1-dependent release of the protein
phosphatase Cdc14 from nucleolar RENT complex. Cell 97:
Sohrmann M, Schmidt S, Hagan I, Simanis V. 1998. Asymmetric
segregation on spindle poles of the Schizosaccharomyces
pombe septum-inducing protein kinase Cdc7p. Genes Dev
Stegmeier F, Amon A. 2004. Closing mitosis: the functions of
the Cdc14 phosphatase and its regulation. Annu Rev Genet
Stegmeier F, Visintin R, Amon A. 2002. Separase, polo kinase,
the kinetochore protein Slk19, and Spo12 function in a net-
work that controls Cdc14 localization during early anaphase.
Cell 108: 207–220.
Tanaka K, Petersen J, MacIver F, Mulvihill DP, Glover DM,
Hagan IM. 2001. The role of Plo1 kinase in mitotic commit-
ment and septation in Schizosaccharomyces pombe. EMBO
J 20: 1259–1270.
Toyn JH, Johnston LH. 1994. The Dbf2 and Dbf20 protein
kinases of budding yeast are activated after the metaphase
to anaphase cell cycle transition. EMBO J 13: 1103–1113.
Valerio-Santiago M, Monje-Casas F. 2011. Tem1 localization to
the spindle pole bodies is essential for mitotic exit and
impairs spindle checkpoint function. J Cell Biol 192: 599–
Visintin R, Amon A. 2001. Regulation of the mitotic exit protein
kinases Cdc15 and Dbf2. Mol Biol Cell 12: 2961–2974.
Visintin R, Craig K, Hwang ES, Prinz S, Tyers M, Amon A. 1998.
The phosphatase Cdc14 triggers mitotic exit by reversal of
Cdk-dependent phosphorylation. Mol Cell 2: 709–718.
Visintin R, Hwang ES, Amon A. 1999. Cfi1 prevents premature
exit from mitosis by anchoring Cdc14 phosphatase in the
nucleolus. Nature 398: 818–823.
Visintin R, Stegmeier F, Amon A. 2003. The role of the polo
kinase Cdc5 in controlling Cdc14 localization. Mol Biol Cell
Wang Y, Ng TY. 2006. Phosphatase 2A negatively regulates
mitotic exit in Saccharomyces cerevisiae. Mol Biol Cell 17:
Wilmeth LJ, Shrestha S, Montano G, Rashe J, Shuster CB. 2010.
Mutual dependence of Mob1 and the chromosomal passen-
ger complex for localization during mitosis. Mol Biol Cell 21:
Yeh E, Skibbens RV, Cheng JW, Salmon ED, Bloom K. 1995.
Spindle dynamics and cell cycle regulation of dynein in the
budding yeast, Saccharomyces cerevisiae. J Cell Biol 130:
Yoshida S, Asakawa K, Toh-e A. 2002. Mitotic exit network
controls the localization of Cdc14 to the spindle pole body in
Saccharomyces cerevisiae. Curr Biol 12: 944–950.
Zachariae W, Schwab M, Nasmyth K, Seufert W. 1998. Control
of cyclin ubiquitination by CDK-regulated binding of Hct1 to
the anaphase promoting complex. Science 282: 1721–1724.
Rock and Amon
1954GENES & DEVELOPMENT