Mammalian Lin-2 (mLin-2)/CASK is a membrane-associated guanylate kinase (MAGUK) and contains multidomain modules that mediate protein-protein interactions important for the establishment and maintenance of neuronal and epithelial cell polarization. The importance of mLin-2/CASK in mammalian development is demonstrated by the fact that mutations in mLin-2/CASK or SAP97, another MAGUK protein, le...

BACKGROUND Heterozygous loss-of-function mutations in the X-linked CASK gene cause progressive microcephaly with pontine and cerebellar hypoplasia (MICPCH) and severe intellectual disability (ID) in females. Different CASK mutations have also been reported in males. The associated phenotypes range from nonsyndromic ID to Ohtahara syndrome with cerebellar hypoplasia. However, the phenotypic spec...

All known protein kinases, except CASK [calcium/calmodulin (CaM)-activated serine-threonine kinase], require magnesium ions (Mg(2+)) to stimulate the transfer of a phosphate from adenosine 5'-triphosphate (ATP) to a protein substrate. The CaMK (calcium/calmodulin-dependent kinase) domain of CASK shows activity in the absence of Mg(2+); indeed, it is inhibited by divalent ions including Mg(2+). ...

Calcium (Ca(2+)) and Calmodulin (CaM)-dependent serine/threonine kinase II (CaMKII) plays a central role in synaptic plasticity and memory due to its ability to phosphorylate itself and regulate its own kinase activity. Autophosphorylation at threonine 287 (T287) switches CaMKII to a Ca(2+) independent and constitutively active state replicated by overexpression of a phosphomimetic CaMKII-T287D...

RATIONALE Mechanisms underlying membrane protein localization are crucial in the proper function of cardiac myocytes. The main cardiac sodium channel, NaV1.5, carries the sodium current (INa) that provides a rapid depolarizing current during the upstroke of the action potential. Although enriched in the intercalated disc, NaV1.5 is present in different membrane domains in myocytes and interacts...

CASK is a unique MAGUK protein that contains an N-terminal CaM-kinase domain besides the typical MAGUK domains. The CASK CaM-kinase domain is presumed to be a catalytically inactive pseudokinase because it lacks the canonical DFG motif required for Mg2+ binding that is thought to be indispensable for kinase activity. Here we show, however, that CASK functions as an active protein kinase even wi...

CASK, a synaptic membrane associated guanylate kinase (MAGUK) protein, acts as a coactivator for transcription factor Tbr-1. Tbr-1 is an essential T-box transcription factor in cerebral cortex development. Presently, the molecular mechanism of the CASK co-activation effect is unclear. Here, we report that CASK interacts with another nuclear protein, CINAP (CASK-interacting nucleosome assembly p...

Purpose Optic nerve hypoplasia (ONH) is the most common cause of childhood congenital blindness in developed nations, yet the fundamental pathobiology of ONH remains unknown. The objective of this study was to employ a 'face validated' murine model to determine the timing of onset and the pathologic characteristics of ONH. Methods Based on the robust linkage between X-linked CASK haploinsuffi...

Neurexins are neuronal cell surface proteins with hundreds of isoforms. In yeast two-hybrid screens for intracellular molecules interacting with different neurexins, we identified a single interacting protein called CASK. CASK is composed of an N-terminal Ca2+, calmodulin-dependent protein kinase sequence and a C-terminal region that is similar to the intercellular junction proteins dlg-A, PSD9...

Ca(2+)/CaM serine/threonine kinase II (CaMKII) is a central molecule in mechanisms of synaptic plasticity and memory. A vital feature of CaMKII in plasticity is its ability to switch to a calcium (Ca(2+)) independent constitutively active state after autophosphorylation at threonine 287 (T287). A second pair of sites, T306 T307 in the calmodulin (CaM) binding region once autophosphorylated, pre...