Parallel RNAi screens across different cell lines identify generic and cell type-specific regulators of actin organization and cell morphology.
BACKGROUND
In recent years RNAi screening has proven a powerful tool for dissecting gene functions in animal cells in culture. However, to date, most RNAi screens have been performed in a single cell line, and results then extrapolated across cell types and systems.


RESULTS
Here, to dissect generic and cell type-specific mechanisms underlying cell morphology, we have performed identical kinome RNAi screens in six different Drosophila cell lines, derived from two distinct tissues of origin. This analysis identified a core set of kinases required for normal cell morphology in all lines tested, together with a number of kinases with cell type-specific functions. Most significantly, the screen identified a role for minibrain (mnb/DYRK1A), a kinase associated with Down's syndrome, in the regulation of actin-based protrusions in CNS-derived cell lines. This cell type-specific requirement was not due to the peculiarities in the morphology of CNS-derived cells and could not be attributed to differences in mnb expression. Instead, it likely reflects differences in gene expression that constitute the cell type-specific functional context in which mnb/DYRK1A acts.


CONCLUSIONS
Using parallel RNAi screens and gene expression analyses across cell types we have identified generic and cell type-specific regulators of cell morphology, which include mnb/DYRK1A in the regulation of protrusion morphology in CNS-derived cell lines. This analysis reveals the importance of using different cell types to gain a thorough understanding of gene function across the genome and, in the case of kinases, the difficulties of using the differential gene expression to predict function.
Liu
Tao
T
MRC Laboratory of Molecular Cell Biology, UCL, London, UK. tao.liu@ucl.ac.uk
Sims
David
D
Baum
Buzz
B
D000199:Actins / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D048430:Cell Shape; D022081:Cell Surface Extensions; D002490:Central Nervous System / Q000166:cytology / Q000201:enzymology; D029721:Drosophila Proteins / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology* / Q000201:enzymology / Q000235:genetics*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D017344:Genes, Insect; D005820:Genetic Testing; D006434:Hemocytes / Q000166:cytology / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D010641:Phenotype; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D034622:RNA Interference; D000097603:Dyrk Kinases
D000199:Actins; D029721:Drosophila Proteins; D017346:Protein Serine-Threonine Kinases; C092066:mnb protein, Drosophila; D000097603:Dyrk Kinases