Steven Sandler

Research Professor

Professor Emeritus

Photo of Steven Sandler

Phone:

413-577-4391

Fax:

413-545-1578

Email:

ssandler@umass.edu

Office:

304B Morrill Science Center IVN

Ph.D.:

Molecular Biology, University of California, Berkeley, 1984

Mailing address:

Steven J. Sander, Ph.D.
Department of Microbiology
418 Morrill Science Center IVN
University of Massachusetts
639 North Pleasant Street
Amherst, MA 01003-9298

Research Interests

Our laboratory is interested in the processes of DNA replication, recombination and cell division in E. coli. In particular, we are interested in how these processes are coordinated. It has been recently shown that replication forks stop for a variety of mundane, housekeeping reasons as they replicate chromosomes. This happens both in prokaryotic and eukaryotic cells. After stopping, these forks need to get repaired. This is thought to occur predominately by homologous recombination. Then after repair, these forks need to get up and running again. A special set of proteins call the Replication Restart Proteins form a multi-subunit complex at a repaired replication fork that helps to reload the replisome. In E. coli, the Replication Restart Proteins include PriA, PriB, PriC, DnaT, DnaC, and DnaB.

Our approach is a combination of genetics, molecular biology, cell biology and genomics. We use the power of genetics to look for connections between replication and recombination. We use molecular biology to engineer the chromosome both physically and genetically to test models for how replication forks collapse and get restarted. We use the Green and Red Fluorescent Proteins to monitor where in the cell do these processes occur and to measure gene expression in individual cells.

Selected Publications

Hayashi JM, Richardson K, Melzer ES, Sandler SJ, Aldridge BB, M. Siegrist S, Morita YS. 2018. Stress-Induced Reorganization of the Mycobacterial Membrane Domain. {mBio}. 9

Jang S, Sandler SJ, Harshey RM. 2012. Mu insertions are repaired by the double-strand break repair pathway of Escherichia coli.. PLoS Genet. 8(4):e1002642.

Richter LV, Sandler SJ, Weis RM. 2012. Two isoforms of Geobacter sulfurreducens PilA have distinct roles in pilus biogenesis, cytochrome localization, extracellular electron transfer, and biofilm formation.. J Bacteriol. 194(10):2551-63.

Massoni SC, Leeson MC, Long J E, Gemme K, Mui A, Sandler SJ. 2012. Factors Limiting SOS Expression in Log-Phase Cells of Escherichia coli.. J Bacteriol. 194(19):5325-33.

Marceau AH, Bahng S, Massoni SC, George NP, Sandler SJ, Marians KJ, Keck JL. 2011. Structure of the SSB-DNA polymerase III interface and its role in DNA replication.. EMBO J. 30(20):4236-47.

Sandler SJI, Figaji AA, Adelson DP. 2010. Clinical applications of biomarkers in pediatric traumatic brain injury.. Childs Nerv Syst. 26(2):205-13.

Long J E, Massoni SC, Sandler SJ. 2010. RecA4142 causes SOS constitutive expression by loading onto reversed replication forks in Escherichia coli K-12.. J Bacteriol. 192(10):2575-82.

Long JE, Renzette N, Sandler SJ. 2009. Suppression of constitutive SOS expression by recA4162 (I298V) and recA4164 (L126V) requires UvrD and RecX in Escherichia coli K-12.. Mol Microbiol. 73(2):226-39.

Handa N, Amitani I, Gumlaw N, Sandler SJ, Kowalczykowski SC. 2009. Single molecule analysis of a red fluorescent RecA protein reveals a defect in nucleoprotein filament nucleation that relates to its reduced biological functions.. J Biol Chem. 284(28):18664-73.

Centore RC, Leeson MC, Sandler SJ. 2009. UvrD303, a hyperhelicase mutant that antagonizes RecA-dependent SOS expression by a mechanism that depends on its C terminus.. J Bacteriol. 191(5):1429-38.

Long J E, Renzette N, Centore RC, Sandler SJ. 2008. Differential requirements of two recA mutants for constitutive SOS expression in Escherichia coli K-12.. PLoS One. 3(12):e4100.

Gruenig MC, Renzette N, Long E, Chitteni-Pattu S, Inman RB, Cox MM, Sandler SJ. 2008. RecA-mediated SOS induction requires an extended filament conformation but no ATP hydrolysis.. Mol Microbiol. 69(5):1165-79.

Renzette N, Sandler SJ. 2008. Requirements for ATP binding and hydrolysis in RecA function in Escherichia coli.. Mol Microbiol. 67(6):1347-59.

Centore RC, Lestini R, Sandler SJ. 2008. XthA (Exonuclease III) regulates loading of RecA onto DNA substrates in log phase Escherichia coli cells.. Mol Microbiol. 67(1):88-101.

Figaji AA, Fieggen AG, Sandler SJI, Argent AC, Le Roux PD, Peter JC. 2007. Intracranial pressure and cerebral oxygenation changes after decompressive craniectomy in a child with traumatic brain swelling.. Childs Nerv Syst. 23(11):1331-5.

Lopper M, Boonsombat R, Sandler SJ, Keck JL. 2007. A hand-off mechanism for primosome assembly in replication restart.. Mol Cell. 26(6):781-93.

Centore RC, Sandler SJ. 2007. UvrD limits the number and intensities of RecA-green fluorescent protein structures in Escherichia coli K-12.. J Bacteriol. 189(7):2915-20.

Renzette N, Gumlaw N, Sandler SJ. 2007. DinI and RecX modulate RecA-DNA structures in Escherichia coli K-12.. Mol Microbiol. 63(1):103-15.

Boonsombat R, Yeh S-P, Milne A, Sandler SJ. 2006. A novel dnaC mutation that suppresses priB rep mutant phenotypes in Escherichia coli K-12.. Mol Microbiol. 60(4):973-83.

Renzette N, Gumlaw N, Nordman JT, Krieger M, Yeh S-P, Long E, Centore R, Boonsombat R, Sandler SJ. 2005. Localization of RecA in Escherichia coli K-12 using RecA-GFP.. Mol Microbiol. 57(4):1074-85.

Sandler SJ. 2005. Requirements for replication restart proteins during constitutive stable DNA replication in Escherichia coli K-12.. Genetics. 169(4):1799-806.

McCool JD, Long E, Petrosino JF, Sandler HA, Rosenberg SM, Sandler SJ. 2004. Measurement of SOS expression in individual Escherichia coli K-12 cells using fluorescence microscopy.. Mol Microbiol. 53(5):1343-57.

Hinds T, Sandler SJ. 2004. Allele specific synthetic lethality between priC and dnaAts alleles at the permissive temperature of 30 degrees C in E. coli K-12.. BMC Microbiol. 4:47.

McCool JD, Long E, Petrosino JF, Sandler HA, Rosenberg SM, Sandler SJ. 2004. Measurement of SOS expression in individual Escherichia coli K-12 cells using fluorescence microscopy.. Mol Microbiol. 53(5):1343-57.

McCool JD, Ford CC, Sandler SJ. 2004. A dnaT mutant with phenotypes similar to those of a priA2::kan mutant in Escherichia coli K-12.. Genetics. 167(2):569-78.

Lloyd JR, Leang C, Hodges Myerson AL, Coppi MV, Cuifo S, Methe B, Sandler SJ, Lovley DR. 2003. Biochemical and genetic characterization of PpcA, a periplasmic c-type cytochrome in Geobacter sulfurreducens.. Biochem J. 369(Pt 1):153-61.

Sandler SJ, McCool JD, Do TT, Johansen RU. 2001. PriA mutations that affect PriA-PriC function during replication restart.. Mol Microbiol. 41(3):697-704.

McCool JD, Sandler SJ. 2001. Effects of mutations involving cell division, recombination, and chromosome dimer resolution on a priA2::kan mutant.. Proc Natl Acad Sci U S A. 98(15):8203-10.

Coppi MV, Leang C, Sandler SJ, Lovley DR. 2001. Development of a genetic system for Geobacter sulfurreducens.. Appl Environ Microbiol. 67(7):3180-7.

Sandler SJ. 2000. Multiple genetic pathways for restarting DNA replication forks in Escherichia coli K-12.. Genetics. 155(2):487-97.

Cox MM, Goodman MF, Kreuzer KN, Sherratt DJ, Sandler SJ, Marians KJ. 2000. The importance of repairing stalled replication forks.. Nature. 404(6773):37-41.

Sandler SJ, Marians KJ. 2000. Role of PriA in replication fork reactivation in Escherichia coli.. J Bacteriol. 182(1):9-13.

Sandler SJ, Marians KJ, Zavitz KH, Coutu J, Parent MA, Clark AJ. 1999. dnaC mutations suppress defects in DNA replication- and recombination-associated functions in priB and priC double mutants in Escherichia coli K-12.. Mol Microbiol. 34(1):91-101.

Liu J, Xu L, Sandler SJ, Marians KJ. 1999. Replication fork assembly at recombination intermediates is required for bacterial growth.. Proc Natl Acad Sci U S A. 96(7):3552-5.

Sandler SJ, Hugenholtz P, Schleper C, DeLong EF, Pace NR, Clark AJ. 1999. Diversity of radA genes from cultured and uncultured archaea: comparative analysis of putative RadA proteins and their use as a phylogenetic marker.. J Bacteriol. 181(3):907-15.

Seitz EM, Brockman JP, Sandler SJ, Clark AJ, Kowalczykowski SC. 1998. RadA protein is an archaeal RecA protein homolog that catalyzes DNA strand exchange.. Genes Dev. 12(9):1248-53.

Brendel V, Brocchieri L, Sandler SJ, Clark AJ, Karlin S. 1997. Evolutionary comparisons of RecA-like proteins across all major kingdoms of living organisms.. J Mol Evol. 44(5):528-41.

Sandler SJ, Satin LH, Samra HS, Clark AJ. 1996. recA-like genes from three archaean species with putative protein products similar to Rad51 and Dmc1 proteins of the yeast Saccharomyces cerevisiae.. Nucleic Acids Res. 24(11):2125-32.

Sandler SJ, Samra HS, Clark AJ. 1996. Differential suppression of priA2::kan phenotypes in Escherichia coli K-12 by mutations in priA, lexA, and dnaC.. Genetics. 143(1):5-13.

Sandler SJ. 1996. Overlapping functions for recF and priA in cell viability and UV-inducible SOS expression are distinguished by dnaC809 in Escherichia coli K-12.. Mol Microbiol. 19(4):871-80.

Hegde S, Sandler SJ, Clark AJ, Madiraju MV. 1995. recO and recR mutations delay induction of the SOS response in Escherichia coli.. Mol Gen Genet. 246(2):254-8.

Sandler SJ. 1994. Studies on the mechanism of reduction of UV-inducible sulAp expression by recF overexpression in Escherichia coli K-12.. Mol Gen Genet. 245(6):741-9.

Sandler SJ, Clark AJ. 1994. Mutational analysis of sequences in the recF gene of Escherichia coli K-12 that affect expression.. J Bacteriol. 176(13):4011-6.

Sandler SJ, Clark AJ. 1994. RecOR suppression of recF mutant phenotypes in Escherichia coli K-12.. J Bacteriol. 176(12):3661-72.

Clark AJ, Sandler SJ. 1994. Homologous genetic recombination: the pieces begin to fall into place.. Crit Rev Microbiol. 20(2):125-42.

Sandler SJ, Clark AJ. 1993. Use of high and low level overexpression plasmids to test mutant alleles of the recF gene of Escherichia coli K-12 for partial activity.. Genetics. 135(3):643-54.

Sandler SJ, Chackerian B, Li JT, Clark AJ. 1992. Sequence and complementation analysis of recF genes from Escherichia coli, Salmonella typhimurium, Pseudomonas putida and Bacillus subtilis: evidence for an essential phosphate binding loop.. Nucleic Acids Res. 20(4):839-45.

Sandler SJ, Clark AJ. 1990. Factors affecting expression of the recF gene of Escherichia coli K-12.. Gene. 86(1):35-43.

Blanar MA, Sandler SJ, Armengod ME, Ream LW, Clark AJ. 1984. Molecular analysis of the recF gene of Escherichia coli.. Proc Natl Acad Sci U S A. 81(15):4622-6.

Clark AJ, Sandler SJ, Willis DK, Chu CC, Blanar MA, Lovett ST. 1984. Genes of the RecE and RecF pathways of conjugational recombination in Escherichia coli.. Cold Spring Harb Symp Quant Biol. 49:453-62.

Research interests - short:

DNA Replication, Recombination and Cell Division in E. coli