Mark S. BretscherMark S. Bretscher – Selected Publications

All publications were accepted without revision, except where noted.

Protein Biosynthesis

Polyribonucleotide-directed protein synthesis using an E. coli cell-free system. Nature, 195, 283-284 (1962), with M. Grunberg-Manago.
The word “codon”, suggested by Francis Crick, is first introduced to the English language here.

The chemical nature of the s-RNA polypeptide complex. J. Mol. Biol. 7, 446-449 (1963).
Together with the next paper, the growing polypeptide is found to be attached to a tRNA molecule, this attachment being through one of the hydroxyl groups on the terminal adenosine of tRNA.

Fractionation of oligolysyl-adenosine complexes derived from poly-lysine attached to s-RNA. J. Mol. Biol. 12, 913-917 (1965).
A study of the products from a polynucleotide-directed cell-free protein synthesizing system. J. Mol. Biol. 8, 38-45 (1964), with F. Sanger and E.J. Hocquard.

Polypeptide chain termination using synthetic polynucleotides. J. Mol. Biol. 14, 634-639 (1965), with H.M. Goodman, J.R. Menninger and J.D. Smith.
It is shown here that the polypeptide products encoded by most synthetic polynucleotide mRNAs remain attached to tRNA; however, some messengers, such as one made of U’s and A’s, results in a high proportion of polypeptides released from tRNA and hence that a termination signal sequence is made of U’s and A’s.

Polypeptidyl-sRibonucleic acid and amino-acyl-sRibonucleic acid binding sites on ribosomes. Nature, 211, 380-384 (1966), with K.A. Marcker.
Evidence is presented that there exist separate sites on ribosomes for aminoacyl- and peptidyl-tRNAs.

A GTP requirement for binding initiator tRNA to ribosomes. Nature, 215, 490-492 (1967) with J.S. Anderson, B.F.C. Clark and K.A. Marcker.
Translocation in protein synthesis: a hybrid structure model. Nature, 218, 675-677 (1968).
It is proposed that, during the translocation event in protein synthesis on ribosomes, a hybrid site is formed composed of part of a ribosomal aminoacyl-tRNA site and part of a peptidyl-tRNA site.

Direct translation of a circular messenger DNA. Nature, 220, 1088-1091 (1968).
One way of recognising the correct AUG in a mRNA for initiating protein synthesis is to thread the mRNA onto the ribosome and then find the first AUG. This paper shows that covalently closed circular messengers can initiate protein synthesis and therefore that there is no obligatory threading step.

Polypeptide chain termination: an active process. J. Mol. Biol. 34, 131-136 (1968).
This paper shows that, if an unreadable codon is encountered, synthesis of the polypeptide chain stops, leaving a peptidyl-tRNA. Hence, termination requires specific recognition of a termination codon to release the polypeptide from tRNA.

Membrane Structure

Human erythrocyte membranes: specific labelling of surface proteins. J. Mol. Biol., 58, 775-781 (1971).
It is shown that only two of the many protein bands visible on an SDS gel of erythrocyte membranes can be labelled from outside the red blood cell — a glycoprotein (“glycophorin”) and a large protein (the anion channel).

A major protein which spans the human erythrocyte membrane. J. Mol. Biol., 59, 351-357 (1971).
The major protein labelled from outside the red blood cell is shown to traverse the membrane and does so with a unique fixed orientation.

Major human erythrocyte glycoprotein spans the cell membrane. Nature New Biology, 231, 229-232 (1971).
The main glycoprotein is similarly shown to traverse the erythrocyte membrane.

Phosphatidyl-ethanolamine: Differential labelling in intact cells and cell ghosts of human erythrocytes by a membrane-impermeable reagent. J. Mol. Biol., 71, 523-528 (1972).
It is discovered here that the amino phospholipids of red blood cells are inaccessible to labelling agents from outside the cell. With other evidence marshalled from the literature in the following paper, an asymmetric bilayer structure for the phospholipids in erythrocyte membranes is proposed. This arrangement further strengthens the view that membranes have a bilayer structure. The editor required the term “lipid asymmetry” to be removed from the original title.

Asymmetrical lipid bilayer structure for biological membranes. Nature New Biology, 236, 11-12 (1972).
Membrane structure: Some general principles. Science, 181, 622-629 (1973).
The picture of the red blood cell membrane, as deduced from recent experiments, is described as well as the likely implications for the arrangement of membranes in general.

Some aspects of membrane structure. In: Perspectives in Membrane Biology, ed. S. Estrada-O and Gitler, C., pub. Academic Press, pp. 3-24 (1974).
A mechanism for bilayer growth is presented which automatically generates an asymmetric phospholipid bilayer; this involves phospholipid synthesis on the cytoplasmic face of the membrane, followed by translocation of choline phospholipids by a “flippase”.

C-Terminal region of the major erythrocyte sialoglycoprotein is on the cytoplasmic side of the membrane. J. Mol. Biol. 98, 831-833 (1975).

Mammalian plasma membranes. Nature, 258, 43-49 (1975), with M.C. Raff.
A general review of membrane structure celebrating the 50th anniversary of Gorter and Grendel’s original proposal for the existence of lipid bilayers in erythrocyte membranes.

Cholesterol and the Golgi apparatus. Science 261, 1280-1281 (1993), with S. Munro.
It is proposed that the Golgi apparatus exists primarily to pump cholesterol out of the endoplasmic reticulum (the ER, where it is synthesised) towards the plasma membrane. A consequence of the different amounts of cholesterol in different cellular membranes is that the bilayer gets thicker from ER to Golgi to plasma membrane. This prevents those transmembrane proteins having a short TM domain from being transported all the way from the ER to the plasma membrane; in this way they become localised to the Golgi apparatus.

Endocytosis, Capping and Cell Locomotion

Directed lipid flow in cell membranes. Nature, 260, 21-23 (1976).
A model is proposed to explain why it is that only extensively cross-linked surface antigens cap on motile cells; the model supposes that large aggregates diffuse too slowly to become randomised against a continual lipid flow in these cells’ plasma membranes, whereas uncross-linked molecules can remain randomly distributed by Brownian motion.

Capping of Exogenous Forssman Glycolipid on Cells. J. Cell Biology, 82, 829-833 (1979), with P.L. Stern.
This paper establishes that glycolipids, inserted into the outer monolayer of a motile cell and then cross-linked with antibodies, can cap. It implies that capping does not require direct interaction with cytoplasmic factors.

Lateral Diffusion in eukaryotic cell membranes. TIBS, 5, 10, VI (1980).

Coated pits act as molecular filters. Proc. Natl. Acad. Sci. USA 77, 4156-4159 (1980), with J.N. Thomson and B.M.F. Pearse.
It is shown that some surface proteins are excluded from plasma membrane coated pits as they bud into the cell. Therefore, as far as these noncirculating proteins are concerned, any effects that the endocytic cycle might have upon them would be seen as a lipid flow.

Membrane recycling by coated vesicles. Ann. Rev. of Biochem. 50, 85-101 (1981), with B.M.F. Pearse.
Transferrin receptor and its recycling in Hela cells. EMBO J. 1, 351-355 (1982), with J. Bleil.
This paper reports the kinetic parameters for the transferrin receptor as it circulates in the endocytic cycle of tissue culture cells.

Surface uptake by fibroblasts and its consequences. Cold Spring Harb. Symp. Quant. Biol., 46, 707-712 (1982).
The proposed connection between lipid or membrane recycling and locomotion of fibroblasts is explained.

Distribution of receptors for transferrin and low density lipoprotein on the surface of giant Hela cells. Proc. Natl. Acad. Sci. USA., 80, 454-458 (1983).
In this and the next paper, evidence is presented that exocytosis of circulating membrane in actively ruffling cells occurs at the ends of their leading lamellae.

Distribution of ferritin receptors and coated pits on giant Hela cells. EMBO J. 2, 599-603 (1983), with J. Nichol Thomson.

Endocytosis: Relation to capping and cell locomotion. Science, 224, 681-686 (1984).
The title speaks for itself. Accepted for publication with a minor change on the 500th day of its submission!

The morphology of endosomes in giant Hela cells. European Journal of Cell Biology, 37, 78-80 (1985), with J.N. Thomson.

A new method for detecting endocytosed proteins. EMBO J. 7, 4087-4092 (1988), with R. Lütter.
A new method is reported which enables both endocytosis and, separately, exocytosis of any surface antigen  to be measured; this method depends on introducing a label, which can be selectively removed at will by reduction, onto surface proteins.

Endocytosis and recycling of the fibronectin receptor in CHO cells. EMBO J. 8, 1341-1348 (1989).
The method for measuring cycling of surface proteins is applied to a selection of integrins in this and the next paper. It is proposed that cycling integrins may be transported to the front of a motile cell, enabling the cell to reuse them for locomotion.

Circulating Integrins: a5b1, a6b4 and Mac-1, but not a3b1, a4b1 or LFA-1. EMBO J. 11, 405-410 (1992).

Distinct endocytotic pathways in epidermal growth factor-stimulated human carcinoma A431 cells. J. Cell Biol. 109, 2731-2739 (1989), with M.A. West and C. Watts.

Cells can use their transferrin receptors to locomote. EMBO J. 11, 383-389 (1992).
This paper sets out to examine whether all that a cell needs for locomotion is a surface molecule which both circulates and can bind to the substratum. A substratum was prepared to which the transferrin receptor could specifically attach; motile cells were able to migrate some distance on this substratum.

Getting membrane flow and the cytoskeleton to cooperate in moving cells. Cell 87, 601-606 (1996).
A review in which the roles microtubules, microfilaments and membrane circulation may have in cell locomotion is presented.

Dictyostelium myosin II null mutant can still cap Con A receptors. Proc. Natl. Acad. Sci. USA 94, 9684-9686 (1997), with C. Aguado-Velasco.
It had been proposed that myosin II is not required for locomotion but is required for capping, thus implying that the two processes are unrelated. This paper shows that myosin II is not required for capping, thereby reestablishing the tight connection between capping and locomotion. This paper was rejected by Nature.

EGF induces recycling membrane to form ruffles. Curr. Biol. 8, 721-724 (1998), with C. Aguado-Velasco.
A hormonally induced ruffle on a mammalian cell is similar to a leading edge because both are enriched in circulating receptors, indicating that they are sites of exocytosis.

Circulation of the plasma membrane in Dictyostelium. Mol. Biol. Cell 10, 4419-4427 (1999), with C. Aguado-Velasco.
The rate of membrane circulation in an amoeba which is capable of very rapid migration was estimated with the dye FM1-43. The measured circulation rate appears fast enough to provide sufficient surface to extend an amoeba’s leading edge, by exocytosis, as it moves. This paper was rejected by the EMBO Journal, Cell, and Molecular Cell.

Cell polarity and locomotion, as well as endocytosis, depend on NSF. Development, 129, 4185-4192 (2002), with C. R. L. Thompson.
This paper shows how ts mutants can be made in essential genes in Dictyostelium amoebae, and that NSF is required for the amoebae to move and maintain their polarity. Rejected by Science and Current Biology (as an article).

Using Single loxP sites to enhance homologous recombination: ts mutants in sec1 of Dictyostelium discoideum. PloS ONE, e724 (2007), with M. Clotworthy.
This paper shows how ts mutants can still be made in the sec1 gene, even when homologous recombination at that site is low. Mutants in this gene, which is believed to be required for exocytosis, fail to move at the restrictive temperature: they are very similar to ts mutants in NSF. An early version rejected by Genetics.

Recap on cell migration. Traffic, 9, 1-2 (2007).
A plea for those interested in cell migration to think about cap formation. Rejected by Nature, Nature Cell Biology, Nature Reviews in Molecular Cell Biology, Journal of Cell Science, Journal of Cell Biology and Trends in Cell Biology.

On the shape of migrating cells – a `front-to-back’ model. J Cell Sci 121: 2625-2628 (2008).

Dictyostelium amoebae and neutrophils can swim. Proc. Natl. Acad. Sci. USA, 107, 11376-11380 (2010), with N.P. Barry.
We show here that these two cell types, principle material for studying locomotion on a substrate, can chemotax in suspension. When doing so they have many similarities to crawling cells, including the formation of lamellipodial veils and similar speed. These cells could only swim with either the rearward movement of pseudopodia and spikes (acting as paddles), or by membrane flow. Rejected by Nature (“insufficient immediate interest”), Science (“far too preliminary and superficial”), Current Biology, Molecular Biology of the Cell (“not interested in such papers ….looking for more complete bodies of work”).

The exocytic gene secA is required for Dictyostelium cell motility and Osmoregulation. J. Cell Sci., 123, 3226-3234 (2010), with R. Zanchi, G. Howard and R.R. Kay.

How do Amoebae swim and crawl? PLOS ONE,  0074382 (2013), with J.D. Howe and N.P.Barry.

Asymmetry of single cells and where that leads. Ann. Rev. Biochemistry, 83, (2014).

Other

Why is phosphate so useful? Symposium in honour of Fritz Lipmann, in: Molecular Biology, Biochemistry and Biophysics: 32, 195-196 (1980).

The molecules of the cell membrane. Scientific American, 253, 86-90 (1985).

How animal cells move. Scientific American, 255, 72-90 (1987).

Francis Crick, Obituary, in The Independent, August 3rd, 2004.

Francis Crick 1916 – 2004. Current Biology 14, R642-645 (2004), with Peter Lawrence.

Arthur Kornberg, Obituary, in The Independent, November 3rd, 2007.

Francis Harry Compton Crick OM. 8 June 1916 – 28 July 2004, Biographical Memoirs of the Fellows of the Royal Society, May 17th, 2017, http://rsbm.royalsocietypublishing.org/content/early/2017/05/22/rsbm.2017.0010