Superscripts (^M,F,Y) refer to the type of organism (mammal, fly,yeast) in which the observation was made. The ARP10 subfamily is italicized to indicate that bootstrap confidence in the validity of the observed grouping is low. However, the observations that mammalian Arp11 is part of dynactin and that Neurospora RO7 protein is required for proper localization and function of dynein (Lee et al.,2001) support the existence of a conserved subfamily.

Yeast localization and deletion phenotype data are summarized byHarata et al., 2000 and the Saccharomyces Genome Database(http://genome-www.stanford.edu/Saccharomyces). No Arp10 deletions have been reported in the literature. Characterization of biochemical associations of conventional actin, ScARP4, ScARP5, ScARP5,ScARP7/9 and HsBAF53 with transcription machinery can be found inCairns et al., 1998;Galarneau et al., 2000;Harata et al., 1999;Park et al., 2002;Peterson et al., 1998;Zhao et al., 1998;Shen et al., 2000. Other primary references for characterization of actin, Arp1, Arp2, Arp3 and individual Arp subfamily members can be found referenced inMachesky and May, 2001;Schafer and Schroer, 1999. Our apologies to those authors we were not able to cite due to space restrictions.