Junction-mediating and regulatory protein (JMY) is a vertebrate protein that was first identified as a transcriptional co-activator of p53 []. It is a regulator of both transcription and actin filament assembly [, , ]. In the nucleus it acts as a transcriptional coactivator and promotes programmed cell death in response to DNA damage [], whereas in the cytoplasm it promotes actin filament assembly []. JMY can either initiate actin filament formation by binding and activating the Arp2/3 complex or nucleate filaments directly in a SPIRE-like fashion [, ]. In both cases, the JMY's actin-regulatory activity relies on a cluster of three actin-binding WH2 domains at its C terminus [].
JMY (junction-mediating and -regulatory protein) []and WHAMM (WASP homologue-associated protein with actin, membranes and microtubules) []are two nucleation-promoting factors (NPFs) with similar domain architecture. JMY was originally identified as a transcriptional co-factor in the p53-response to DNA damage. Aside from this nuclear function, JMY is involved in cytoskeleton remodelling and trans-Golgi transport []. WHAMM binds microtubules and is involved in ER to cis-Golgi transport []. JMY and WHAMM show similar localisation and could be involved in similar processes []. This middle domain is the coiled-coil region that putatively binds microtubules to the scaffold. This ability to interact with microtubules plays a role in membrane tubulation.
This is the N-terminal domain of WHAMM (WASP homologue-associated protein with actin, membranes and microtubules) and JMY (junction-mediating and -regulatory protein), two nucleation-promoting factors (NPFs) with similar domain architecture []. The function of this conserved region is not known; there are two highly conserved tryptophan residues.
