John Mekalanos is a microbiologist who is primarily known for leading one of the first teams that reported the discovery of the type VI secretion system as well as his work on the pathogenicity of the bacterial species ''

Vibrio cholerae ''Vibrio cholerae'' is a species of Gram-negative, facultative anaerobe and comma-shaped bacteria. The bacteria naturally live in brackish or saltwater where they attach themselves easily to the chitin-containing shells of crabs, shrimps, and oth ...

'', its

toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849 ...

, and its secretion systems. Since 1998, he has been a member of the National Academy of Sciences.

Education

He started his research studies as a graduate student in the labs of R. John Collier and William Robert Romig at

UCLA The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the California ...

where his research was focused on studying the genetic and biochemical analysis of the cholera toxin secreted by the bacterium ''

''. Highlights of his career during this time was, along with Romig, the development of a screening assay designed to isolate the tox mutants of ''Vibrio cholerae'' (strains with altered toxin production ability) which led to the genetic mapping of the toxin-regulatory mutants in this bacterial species. He continued his work on cholera toxin as a post-doc at the Department of Microbiology and Molecular Genetics at

Harvard Medical School Harvard Medical School (HMS) is the graduate medical school of Harvard University and is located in the Longwood Medical Area of Boston, Massachusetts. Founded in 1782, HMS is one of the oldest medical schools in the United States and is consi ...

with John R. Murphy, which was followed by his appointment as an assistant professor there.

Career and Research

Early Research

His early work as an independent researcher led to the identification of ''toxR'', a gene that affects the expression of the cholera toxin operon ''ctxAB'', the discovery that the Staphylococcus aureus enterotoxin A (''entA'') is a phage-encoded protein, and finally, the demonstration of the presence of duplications of the toxin operon in different strains of ''Vibrio cholerae'' that could account for the variable toxinogenicity of the strains which led to his promotion to Professor in 1986. His continued strong research output led to his appointment as Chairman of the then Department of Microbiology and Molecular Genetics (now Microbiology) ten years later in 1996 and his election to the National Academy of Sciences in 1998.

T6SS Discovery

In 2006, his group published the first account of the identification of a novel secretion system that they named the type VI secretion system, a system initially found to be capable of conferring increased virulence in non-O1/non-O139 strain strains of ''V. cholerae'', which was later however shown to be primarily responsible for interbacterial competition.

Awards and honors

* Eli Lilly and Company-Elanco Research Award (1991) * AAAS

Newcomb Cleveland Prize The Newcomb Cleveland Prize of the American Association for the Advancement of Science (AAAS) is annually awarded to author(s) of outstanding scientific paper published in the Research Articles or Reports sections of ''Science''. Established in 192 ...

(1993) * Elected to the National Academy of Sciences (1998) * Elected to the

American Academy of Microbiology The American Society for Microbiology (ASM), originally the Society of American Bacteriologists, is a professional organization for scientists who study viruses, bacteria, fungi, algae, and protozoa as well as other aspects of microbiology. It wa ...

(1999)

References

American microbiologists {{biologist-stub