A study of neuronal ceroid lipofuscinosis proteins CLN5 and CLN8

K-REx Repository

Show simple item record

dc.contributor.author De Silva, Weerakonda Arachchige Bhagya Nilukshi
dc.date.accessioned 2017-06-30T18:35:35Z
dc.date.available 2017-06-30T18:35:35Z
dc.date.issued 2015-08-01 en_US
dc.identifier.uri http://hdl.handle.net/2097/35749
dc.description.abstract Neuronal ceroid lipofuscinoses (NCLs) are a group of neurodegenerative lysosomal storage disorders which is the most frequent group of inherited neurodegenerative disorders that affect children leading to severe pathological conditions such as progressive loss of motor neuron functions, loss of vision, mental retardation, epilepsy, ataxia and atrophy in cerebral, cerebella cortex and retina and eventually premature death. Among the many genes that cause NCL, mutations in CLN5 leads to different forms of NCL (infantile, late infantile, juvenile and adult) and mutations in CLN8 leads to progressive epilepsy with mental retardation (EPMR) and a variant late infantile form of NCL. The function(s) of both CLN5 and CLN8 proteins remain elusive. CLN5 is a glycosylated soluble protein that resides in the lysosome. We observed that endogenous CLN5 protein exist in two forms and identified a previously unknown C-terminal proteolytic processing event of CLN5. Using a cycloheximide chase experiment we demonstrated that the proteolytic processing of CLN5 is a post-translational modification. Furthermore treatment with chloroquine showed the processing occurs in low pH cellular compartments. After treatment with different protease inhibitors our results suggested the protease involved in the processing of CLN5 could be a cysteine protease. Using two glycosylation mutants of CLN5, retained in the endoplasmic reticulum (ER) or the Golgi we showed the proteolytic processing occurs in an organelle beyond the ER. This study contributes to understanding the characteristics of the CLN5 protein. CLN8 is an ER resident transmembrane protein that shuttles between the ER and the ER-Golgi intermediate compartment (ERGIC). In our study we identified a potential interaction between CLN8 and a PP2A holoenzyme complex consisting regulatory subunit A α isoform and regulatory subunit B α isoform. Using two CLN8 patient derived fibroblast cell lines we were able to show that the phosphorylated levels of PP2A target kinase Akt was reduced at both of its regulatory sites Ser473 and Thr308 and the activity of PP2A was increased. A delay of ceramide transport from ER to Golgi in CLN8 deficient patient cell lines was observed using BODIPY FL C5-Ceramide staining. Our results provide evidence for CLN8 protein being involved in the regulation of PP2A activity and trafficking of ceramide from ER to Golgi. en_US
dc.language.iso en_US en_US
dc.publisher Kansas State University en
dc.subject Lysosomal storage disorder en_US
dc.subject Neuronal ceroid lipofuscinosis en_US
dc.subject CLN5 en_US
dc.subject CLN8 en_US
dc.title A study of neuronal ceroid lipofuscinosis proteins CLN5 and CLN8 en_US
dc.type Thesis en_US
dc.description.degree Master of Science en_US
dc.description.level Masters en_US
dc.description.department Biochemistry and Molecular Biophysics Interdepartmental Program en_US
dc.description.advisor Stella Yu-Chien Lee en_US
dc.date.published 2015 en_US
dc.date.graduationmonth August en_US

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search K-REx

Advanced Search


My Account


Center for the

Advancement of Digital


118 Hale Library

Manhattan KS 66506

(785) 532-7444