Irazoqui JE (2015) Immunity "Why worms watch their hemidesmosomes and why you should, too."

Irazoqui JE

[Immunity, 2015]

Hemidesmosomes are cellular attachment structures of great importance to the epidermis. In this issue of Immunity, Zhang et al. (2015) have discovered that in addition to having structural functions, invertebrate and human hemidesmosomes are actively monitored by the cell as a novel mechanism for detecting pathogenic infection.

Kumsta C et al. (2019) J Cell Biol "Getting under the skin: Cuticle damage elicits systemic autophagy response in C. elegans."

Hansen M, Kumsta C

[J Cell Biol, 2019]

In this issue, Zhang et al. (2019. <i>J. Cell. Biol.</i> https://doi.org/10.1083/jcb.201907196) describe a molecular mechanism by which cuticular damage in the nematode <i>C. elegans</i> leads to systemic induction of autophagy by signals propagated from sensory neurons via the TGF- signaling pathway.

Leiser SF et al. (2016) Worm "New insights into cell non-autonomous mechanisms of the C. elegans hypoxic response."

Leiser SF, Rossner R, Kaeberlein M

[Worm, 2016]

The hypoxic response is a well-studied and highly conserved biological response to low oxygen availability. First described more than 20 y ago, the traditional model for this response is that declining oxygen levels lead to stabilization of hypoxia-inducible transcription factors (HIFs), which then bind to hypoxia responsive elements (HREs) in target genes to mediate the transcriptional changes collectively known as the hypoxic response.(1,2) Recent work in C. elegans has forced a re-evaluation of this model by indicating that the worm HIF (HIF-1) can mediate effects in a cell non-autonomous fashion and, in at least one case, increase expression of an intestinal hypoxic response target gene in cells lacking HIF-1.

Nurrish S (2014) Genetics "Dense core vesicle release: controlling the where as well as the when."

Nurrish S

[Genetics, 2014]

Ca(2+)/calmodulin-dependent Kinase II (CaMKII) is a calcium-regulated serine threonine kinase whose functions include regulation of synaptic activity (Coultrap and Bayer 2012). A postsynaptic role for CaMKII in triggering long-lasting changes in synaptic activity at some synapses has been established, although the relevant downstream targets remain to be defined (Nicoll and Roche 2013). A presynaptic role for CaMKII in regulating synaptic activity is less clear with evidence for CaMKII either increasing or decreasing release of neurotransmitter from synaptic vesicles (SVs) (Wang 2008). In this issue Hoover et al. (2014) further expand upon the role of CaMKII in presynaptic cells by demonstrating a role in regulating another form of neuronal signaling, that of dense core vesicles (DCVs), whose contents can include neuropeptides and insulin-related peptides, as well as other neuromodulators such as serotonin and dopamine (Michael et al. 2006). Intriguingly, Hoover et al. (2014) demonstrate that active CaMKII is required cell autonomously to prevent premature release of DCVs after they bud from the Golgi in the soma and before they are trafficked to their release sites in the axon. This role of CaMKII requires it to have kinase activity as well as an activating calcium signal released from internal ER stores via the ryanodine receptor. Not only does this represent a novel function for CaMKII but also it offers new insights into how DCVs are regulated. Compared to SVs we know much less about how DCVs are trafficked, docked, and primed for release. This is despite the fact that neuropeptides are major regulators of human brain function, including mood, anxiety, and social interactions (Garrison et al. 2012; Kormos and Gaszner 2013; Walker and Mcglone 2013). This is supported by studies showing mutations in genes for DCV regulators or cargoes are associated with human mental disorders (Sadakata and Furuichi 2009; Alldredge 2010; Quinn 2013; Quinn et al. 2013). We lack even a basic understanding of DCV function, such as, are there defined DCV docking sites and, if so, how are DCVs delivered to these release sites? These results from Hoover et al. (2014) promise to be a starting point in answering some of these questions.