scholarly journals Proliferating cell nuclear antigen (pol30) mutations suppress cdc44 mutations and identify potential regions of interaction between the two encoded proteins.

1994 ◽  
Vol 14 (7) ◽  
pp. 4390-4397 ◽  
Author(s):  
M A McAlear ◽  
E A Howell ◽  
K K Espenshade ◽  
C Holm

In addition to its role as a processivity factor in DNA replication, proliferating cell nuclear antigen (PCNA) may function in the regulation of cell cycle progression. We present genetic evidence that PCNA interacts with the gene product of CDC44, an essential nucleotide-binding protein that encodes the large subunit of yeast replication factor C (K. Fien and B. Stillman, personal communication). Mutations in POL30 (PCNA) suppress cold-sensitive alleles of cdc44 that contain mutations in or near nucleotide-binding consensus domains, but they do not suppress a null allele. Thus, it appears that PCNA interacts with Cdc44p but cannot substitute for its function. pol30 mutations suppress additional phenotypes of cdc44 mutations, including the cold sensitivity that they were selected to suppress. This observation suggests an intimate association between PCNA and Cdc44p. Each of five independent pol30 mutants contains a unique single mutation that maps to a localized region on one face of the predicted three-dimensional structure of PCNA. This face identifies a region likely to be important for functional interaction between the CDC44 and POL30 gene products.

1994 ◽  
Vol 14 (7) ◽  
pp. 4390-4397
Author(s):  
M A McAlear ◽  
E A Howell ◽  
K K Espenshade ◽  
C Holm

In addition to its role as a processivity factor in DNA replication, proliferating cell nuclear antigen (PCNA) may function in the regulation of cell cycle progression. We present genetic evidence that PCNA interacts with the gene product of CDC44, an essential nucleotide-binding protein that encodes the large subunit of yeast replication factor C (K. Fien and B. Stillman, personal communication). Mutations in POL30 (PCNA) suppress cold-sensitive alleles of cdc44 that contain mutations in or near nucleotide-binding consensus domains, but they do not suppress a null allele. Thus, it appears that PCNA interacts with Cdc44p but cannot substitute for its function. pol30 mutations suppress additional phenotypes of cdc44 mutations, including the cold sensitivity that they were selected to suppress. This observation suggests an intimate association between PCNA and Cdc44p. Each of five independent pol30 mutants contains a unique single mutation that maps to a localized region on one face of the predicted three-dimensional structure of PCNA. This face identifies a region likely to be important for functional interaction between the CDC44 and POL30 gene products.


1999 ◽  
Vol 19 (2) ◽  
pp. 1038-1048 ◽  
Author(s):  
Hiroyuki Tanaka ◽  
Koichi Tanaka ◽  
Hiroshi Murakami ◽  
Hiroto Okayama

ABSTRACT At the nonpermissive temperature the fission yeastcdc24-M38 mutant arrests in the cell cycle with incomplete DNA replication as indicated by pulsed-field gel electrophoresis. Thecdc24 + gene encodes a 501-amino-acid protein with no significant homology to any known proteins. The temperature-sensitive cdc24 mutant is effectively rescued by pcn1 +, rfc1 + (a fission yeast homologue of RFC1), andhhp1 +, which encode the proliferating cell nuclear antigen (PCNA), the large subunit of replication factor C (RFC), and a casein kinase I involved in DNA damage repair, respectively. The Cdc24 protein binds PCNA and RFC1 in vivo, and the domains essential for Cdc24 function and for RFC1 and PCNA binding colocalize in the N-terminal two-thirds of the molecule. In addition,cdc24 + genetically interacts with the gene encoding the catalytic subunit of DNA polymerase ɛ, which is stimulated by PCNA and RFC, and with those encoding the fission yeast counterparts of Mcm2, Mcm4, and Mcm10. These results indicate that Cdc24 is an RFC- and PCNA-interacting factor required for DNA replication and might serve as a target for regulation.


1999 ◽  
Vol 181 (21) ◽  
pp. 6591-6599 ◽  
Author(s):  
Isaac K. O. Cann ◽  
Sonoko Ishino ◽  
Ikuko Hayashi ◽  
Kayoko Komori ◽  
Hiroyuki Toh ◽  
...  

ABSTRACT Proliferating cell nuclear antigen (PCNA) is an essential component of the DNA replication and repair machinery in the domainEucarya. We cloned the gene encoding a PCNA homolog (PfuPCNA) from an euryarchaeote, Pyrococcus furiosus, expressed it in Escherichia coli, and characterized the biochemical properties of the gene product. The protein PfuPCNA stimulated the in vitro primer extension abilities of polymerase (Pol) I and Pol II, which are the two DNA polymerases identified in this organism to date. An immunological experiment showed that PfuPCNA interacts with both Pol I and Pol II. Pol I is a single polypeptide with a sequence similar to that of family B (α-like) DNA polymerases, while Pol II is a heterodimer. PfuPCNA interacted with DP2, the catalytic subunit of the heterodimeric complex. These results strongly support the idea that the PCNA homolog works as a sliding clamp of DNA polymerases in P. furiosus, and the basic mechanism for the processive DNA synthesis is conserved in the domainsBacteria, Eucarya, and Archaea. The stimulatory effect of PfuPCNA on the DNA synthesis was observed by using a circular DNA template without the clamp loader (replication factor C [RFC]) in both Pol I and Pol II reactions in contrast to the case of eukaryotic organisms, which are known to require the RFC to open the ring structure of PCNA prior to loading onto a circular DNA. Because RFC homologs have been found in the archaeal genomes, they may permit more efficient stimulation of DNA synthesis by archaeal DNA polymerases in the presence of PCNA. This is the first stage in elucidating the archaeal DNA replication mechanism.


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