Careers in science and engineering

SpKAP115 and armadillo repeats suggests that they are both mostly alpha helical (data not shown). These results strongly suggest that SpKAPl15 is the first example of an armadillo-repeat protein directly involved in microtubule-based intracellular transport. What are the implications of the finding that SpKAPl15 is an armadillo-repeat protein? Such proteins are involved in a wide variety of processes, but most is known about their role in intracellular signallinglO, where they form a multiplicity of protein-protein interactions in various signalling pathways. For example, the transmembrane adhesion molecule E-cadherin and the cytosolic tumour-suppressor gene product APC compete for binding of the armadillo-repeat protein B-catenin, the vertebrate homologue of Drosophila ARMADILLO. Furthermore, the stability of E-cadherin-J3-catenin complexes is enhanced by Wnt-1 signalling but reduced by v-Srcdependent phosphorylation of J3-catenin (reviewed in Ref. 11). A second armadillo-repeat protein involved in microtubule-based processes is PFI 6, a Ch/amydomonas protein proposed to mediate protein-protein interactions necessary for stability of the Cl central microtubule and for flagellar motility12. However, PFl6 is not believed to participate directly in microtubule motility; instead, it may be a structural component of the flagella12. The presence of armadillo repeats in SpKAPl 15 is consistent with its proposed function as the kinesin-II cargo-binding site. Yamazaki et al. have recently reported the

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Careers in science and engineering In her article entitled ‘Competition is not our enemy’ in the July 1996 issue of trends in CELL BIOLOGY (Ref. 1), Sandra Schmid discussed how best to address the problem of there apparently being insufficient academic positions available for all the graduate students and

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molecular characterization of KAP3, the mouse homologue of SpKAP115 (Ref. 13), and we have confirmed that KAP3, like SpKAPl15, harbours armadillo repeats (data not shown). The conservation of the predicted structure of SpKAPl 15 and KAP3 suggests that armadillo repeats are an important component of the kinesin-II holoenzyme. One can envisage a model in which the interaction of SpKAPl15/KAP3 with their intracellular cargoes is regulated in a manner similar to that observed for other armadillo-repeat protein-protein interactions. More speculatively, we propose that the cargo-bound receptors of SpKAPl 1S/RAP3 may be related in primary or secondary structure to previously identified proteins, such as E-cadherin and APC, known to interact with armadillo-repeat proteins14,15.

HIROKAWA, N. (1996) Trends Cell Bid. 6, 135-141 6 GOLDSTEIN, L. S. B. (1993) Annu. Rev. Cenet. 27, 319-351 7 CINDHART, 1. G., Jr and GOLDSTEIN, L. 5. 8. (1996) Trends Biochem. Sci. 21,52-53 8 ALTSHUL, S. F., CISH, W., MILLER, W., MYERS, E. W. and LIPMAN, D. 1. (1990) 1. Mol. Biol. 215, 403-410 9 PEIFER, M., BERG, S. and REYNOLDS, A. B. (1994) Cell 76, 789-791 10 PEIFER, M., ORSULIC, S., PAI, L-M. and LOURIERO, J. (1993) Development (Suppl.), 163-l 76 11 RANSCHT, B. (1994) Curr. Opin. Cell Biol. 6, 740-746 12 SMITH, E. F. and LEFEBRE, P. A. (1996) 5

1. Cell Biol. 132, 359-370

13

14 15

Acknowledgements This work was supported by the NIH. The authors thank Roman Sakowicz for his sage advice and encouragement. We apologize to those authors whose work, owing to space limitations, has not been cited directly. L. S. B. C. is an Investigator of the Howard Hughes Medical Institute.

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References 1 GOLDSTEIN, L. S. 6. (1993) Trends Cell Biol. 1, 93-98 2 COY, D. L. and HOWARD, 1. (1994) Curr. Opin. Neurobiol. 4, 662-667 3 SCHOLEY, 1. M. (1996) 1. Cell Biol. 133, l-4 4 WEDAMAN, K. P., MEYER, D. W., RASHID, D. I., COLE, D. G. and SCHOLEY, 1. M. (1996) I. Cell Biol. 132, 371-380

postdoctoral researchers currently pursuing careers in science. She suggested that, rather than trying to restrict the number of students admitted to graduate school, we should apply more rigorous criteria to career decisions at various stages during a graduate student’s training and provide information about alternative applications of the training obtained so that young researchers can consider nonacademic career paths and adapt their training goals accordingly. trends

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YAMAZAKI, H., NAKATA, T., OKADA, Y. and HIROKAWA, N. (1996) Proc. Nat/. Acad. Sci. IJ. S. A. 93, 8443-8448 DANIEL, J. M. and REYNOLDS, A. B. (1995) Mol. Cell. Biol. 15, 4819-4824 RUBINFIELD, B., SOUZA, B., ALBERT, I,, MUNEMITSU, 5. and POLAKIS, P. (1995) j.Biol. Chem.270,5549-5555 BLOOM, C. 5. and ENDOW, S. (1994) Protein Profile 1, 1059-1116 DEVEREUX, J., HAEBERLI, P. and SMITHIES, 0. (1984) NucleicAcids Res. 12, 387-395 BAILEY, T. L. and ELKAN, C. (1995) IAMB 3,21-29 THOMPSON, 1. D., HIGGINS, D. G. and GIBSON, T. 1. (1994) Nucleic Acids Rex 22, 467311680 ROST, B.(1996) Methods Enzymol. 266, 525-539

Joseph G. Cindhart, Jr and Lawrence S. B. Goldstein Howard Hughes Medical Institute, Division of Cellular and Molecular Medicine, Dept of Pharmacology, UCSD School of Medicine, 9500 Gilman Drive 0683, La Jolla, CA 92093-0683, USA.

The Committee on Science, Engineering, and Public Policy (COSEPUP) of the National Academy of Sciences, National Academy of Engineering and Institute of Medicine supports these proposals. As stated in its report ‘Reshaping the Graduate Education of Scientists and Engineers’ (available on the World Wide Web, see Box 1), COSEPUP saw no reason to recommend across-the-board limits on enrolment. Several factors argue against such action: conditions differ greatly by in CELL BIOLOGY

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BOX field and subfield; an extensive, disciplined research experience provides a valuable preparation for a wide variety of non-traditional careers for which scientific and technical expertise is relevant; and limiting actions would have little immediate aggregate impact even if they could be orchestrated effectively. Instead, COSEPUP believes that improved career information and guidance will enhance the ability of the system to balance supply and demand. COSEPUP believes that students should be encouraged to consider three alternative pathways at the point when they have met their qualifying requirements. First, to stop with a master’s degree, in light of their aspirations and employment demands. Second, to proceed towards a PhD and a position in research. Third, for a student interested in working in nontraditional fields, to design a PhD dissertation that meets high standards for originality but requires less time to prepare than one intended as a basis for a career in academic research. COSEPUP believes that the first option is typically undervalued and the third is often neglected. COSEPUP has developed a student guide entitled ‘Careers in Science and Engineering: A Student Planning

Guide to Grad School and Beyond’ (see Box 1 for the WWW address). This guide provides students with the information they need to plan their careers, particularly careers in non-academic settings, and discusses how to obtain the education and skills necessary to attain their career goals. It also contains profiles of science and engineering professionals to illustrate a variety of career paths. In addition, the Academies have developed a WWW site called ‘A Career Planning Center for Beginning Scientists and Engineers’ (see Box 1). This site provides online information and guidance about career options as well as a listing of employment opportunities. Guidance such as this is coming not only from the Academies, but from many scientific and engineering disciplinary societies. Links to these societies can be found at our career planning centre and many are highlighted in a forthcoming report based on our recent ‘National convocation on science and engineering doctoral education’, which can be accessed online from the career planning centre mentioned above once it is available.

Reference 1

SCHMID,

SITES AND INFORMATION

Reshaping the Graduate Education of Scientists and Engineers

http://www.nap.edu/nap/ online/grad/ Careers in Science and Engineering: A Student Planning Guide to Grad School and Beyond

http://www.nap.edu/nap/ online/careers/ A Career Beginning

Planning Center Scientists and

for Engineers

http://www2.nas.edu/cpc Written copies of the reports can also be obtained at a cost from the National Academy Press, 2101 Constitution Avenue NW, Box 285, Washington DC 20055, USA. Telephone: I-800-624-6242 +I -202-334-3313

Bruce

(in the USA), (worldwide)

Alberts

President

Deborah

Stine

Associate Director, Committee on Science, and Public Policy

Engineering,

National Academy of Sciences, 2101 Constitution Avenue NW, Washington DC 20418, USA.

in trends in CELL BIOLOGY...

a new series on ceil adhesion

David Cheresh on the role of cell adhesion comment

Trends Cell Biol. 6,

257-258

Next month we will be starting

S. L. (1996)

1 - WWW OTHER

with a review by Staffan Strdmblad

molecules

in angiogenesis,

and

plus a complementary

by Ceorg Breier and Werner Risau on the role of VEGF in blood vessel formation.

There will also be a comment

article on the role of endocytosis

in lentiviral (HlV/SlV) replication;

plus reviews on vesicle coats, cytoplasmic chaperones and the intercellular bridges called ring canals that form during Drosophila oogenesis. The Drosophila ring canals are illustrated in the picture below, which was kindly provided by the authors of the review, Douglas Robinson and Lynn Cooley from the Department

of Genetics, Yale University, USA. This shows a

stage 6 Drosophila egg chamber stained for actin with rhodamineconjugated

phalloidin

(red) and for KELCH with

antibodies (green) - overlapping

monoclonal

expression of these proteins in

the ring canals appears as yellow. The KELCH protein is specifically located in the ring canals.

trends

in CELL BIOLOGY

(Vol.

6) November

1996