this exciting story of nerve growth inhib-

itors. Besides molecules, there is more

and more evidence suggesting that

the physical properties of the environ-

ment, such as electrical fields, may

also affect biological activity. Several

possible hypotheses explaining these

phenomena are elaborated elegantly

by the authors in Chapter 9 and 10. Using molecular genetics and physio-

logical approaches, much progress has

been made in the past few years

towards identifying specific proteins and the corresponding signalling path-

ways involved in neuronal pathfinding

(Chapters 2 and 3). Goldberg’s group

Chf-Hung Lin from Columbia University has found

Dept of strong protein tyrosine phosphorylation

Microbiology and at the tips of filopodia (Chapter 2), indi-

Immunology, eating a role for kinases in modulating

National growth cone movement. This finding

Yang-Ming meshes nicely with functional studies

University, of protein tyrosine kinase by Baldwin,

Taipei 112, Taiwan. Wash and Doherty(Chapter 3)Through

their continuous efforts, Wash and

Doherty’s group have examined sys-

tematically the signalling pathways of

the cell-adhesion molecules. Among

their findings, the role of protein tyro-

sine kinase in transducing signals from

cell-adhesion molecules to promote

neurite outgrowth has become one of

the most exciting stories (Chapter 3).

In Chapter 5, Davenport and colleagues

describe performing serial Ca2+ imag-

ing on neurons using high-temporal

and -spatial resolution Ca2+-imaging techniques. They provide evidence

that a substructure of the growth cone,

a single filopodium, may function as a

signal-transduction unit during growth

cone guidance.

To summarize, growth cones may be

viewed as signal-transduction devices

that interpret extracellular signals and

then physically direct neurite outgrowth

(i.e. control advance, withdrawal, turn-

ing, branching, etc.). Despite relatively

ample information on membrane recep

tors and associated signalling path-

ways during axonal guidance, much

less is known about the mechanisms

by which cytoskeletal protein dynamics

generate the morphological changes

and movement that occur during

growth cone guidance. In Chapter 4,

Gordon-Weeks and colleagues pre- sent and discuss carefully what we

know about microtubule dynamics in

the growth cone. They emphasize the

role of various microtubule-associated proteins (MAPS) in the regulation of

microtubule structure and point out

the importance of interactions between

microtubules and actin filaments in

controlling biological activities. I have

only one concern: that the actin cyto-

skeleton in the growth cone, consider-

ing its high abundance in the growth

cone and its emerging role as a motil-

ity mediator, could have been reviewed

separately in this book.

Getting it right: chaperonins

Chaperonins

edited by R. John Ellis, Academic

Press, 7996. f59.00 (323 pages)

ISBNO 72237455X

‘Getting it right’ is (in part) the pur-

pose both of this book and its subject.

On the one hand, chaperonins are an

oligomeric subclass of molecular

chaperone that help cells to fold and

assemble other proteins correctly. On

the other, undergraduate textbook ‘bibles’ persist, even now, in convey-

ing the message that the primary

structure of a polypeptide is sufficient

for determining its three-dimensional

folding. Hence, this book is especially

timely because it should help lead to

a sea change in this view - namely that

assistance from molecular chaperones

in many cases, and especially within

the special environment of the cell (as

Martin J. Carden opposed to the ‘protein folder’s’ test

Dept of tube), may absolutely be required for

Biosciences, The adoption of native structure by many

University of Kent proteins following synthesis and/or

at Canterbury, perturbation of their structure by

UK CT2 7NJ. external stresses.

It is most appropriate that Academic

Press should select R. John Ellis (of

Warwick University, UK) to edit this

monograph in its cell biology series

since, over the past decade or more,

he has been a major standard-bearer

for the concept of the chaperonin and

also has written some of the most

influential reviews thereon. His open-

ing chapter is, indeed, a very coherent

and convincingly argued case for the

importance (and underrated status) of

chaperonins in modern cell-biological

thought. This chapter is also a much

better review of the monograph’s pur-

pose and content than I have space

to dwell on here. Ellis has carefully

selected the authors of the various

other chapters as particular experts on

each aspect of chaperonins. While there

are some notables absent, it is a testa-

ment to the strength of British cell

biology in this particular field that so

many of these authors are not only

British but also deservedly recognized

as the ‘world experts’.

While the field (chaperonins) has far

to go and much still to discover about

functions, mechanism and substrates,

the past decade has seen much discov-

ered - enough to justify as particularly

timely the collecting of accumulated

knowledge together into this mono- graph. It is surprisingly (for an edited

volume) up to date and authoritative

on most aspects, as well as moderately

even-handed in presenting alternative

views (e.g. on mechanistic details) and

suggesting where research efforts need

still be applied. Almost every aspect of

chaperonin function is covered in one

of the ten chapters, although perhaps

the least clear picture is presented in

the final chapter (immunological as-

pects of chaperonins), in part reflecting

a relative dearth of research effort so far

in this area. There are some other minor

criticisms regarding authors either err-

ing on the side of caution or else simply

choosing to ignore some of the more

controversial ideas in this field, an ex-

ample being the role and significance

of the ‘football’ form of the GroEL-

GroES oligomer. While other chapters

suffer somewhat in the same way (leav-

ing certain findings undiscussed), this

is to no degree more than in similar

monographs, and, as a whole, the pic-

ture presented is authoritative. For this

reason, and the aforementioned situ-

ation where protein folding in most

textbooks fails to mention chaperonins

and other molecular chaperones, the

monograph will be a valuable addition

to the shelves of any self-respecting

bioscience library.

This monograph is an excellent over-

view (and in places quite detailed

review) of its subject and I recommend

it wholeheartedly to anyone interested

in protein folding, assembly and/or

synthesis generally and in chaperonins

in particular. I expect my copy to

reside on my laboratory shelf (and to

be referred to frequently) for the next

few years to come at least.

174 Copyright 0 1997 Elsevier Science Ltd. All rights reserved. 0962-8924/97/$17.00 trends in CELL BIOLOGY (Vol. 7) April 1997