p38δ MAPK: Emerging Roles of a Neglected Isoform

Table 1

Known p38δ MAPK substrates and their biochemical functions.

Substrate	Function	Consequences of phosphorylation
AP1	Transcription factor	Activation of transcription, involucrin expression, keratinocyte differentiation [58]
ATF2	Transcription factor	Activation of transcription [7, 9]
C/EBP	Transcription factor	Keratinocyte differentiation [59]
c-myb	Transcription factor	c-myb degradation [109]
eEF2K	Inhibitory kinase	eEF2 activation, protein synthesis [53]
Elk1	Transcription factor	Activation of transcription [7, 9]
p53	Transcription factor	p21 expression, G1 phase arrest [9, 110]
PHAS-1	Translation repressor	Dissociation from eIF4E, activation of translation [7]
PRKD1	Serine-threonine kinase	Inhibition of PRKD1 activity [72]
SAP-1	Transcription factor	Activation of transcription [9]
SAP-2	Transcription factor	Activation of transcription [9]
Stathmin	Microtubule protein	Cytoskeleton reorganisation [50]
Tau	Microtubule protein	Microtubule assembly, tau self-aggregation [46]
TonEBP/OREBP	Transcription factor	Impaired TonEBP/OREBP transcriptional activity [41]

AP1: activator protein 1; ATF2: activating transcription factor 2; C/EBP: CCAAT (cytosine-cytosine-adenosine-adenosine-thymidine)-enhancer-binding protein; myb: myeloblastosis; eEF2K: eukaryotic elongation factor 2 kinase; eEF2: eukaryotic elongation factor 2; PHAS-1: phosphorylated heat- and acid-stable protein 1; PRKD1: protein kinase D 1; SAP: serum response factor accessory protein; eIF4E: eukaryotic translation initiation factor 4E.