TY - GEN
T1 - Klotho-Related Protein KLrP
T2 - Structure and Functions
AU - Hayashi, Y.
AU - Ito, M.
N1 - Funding Information:
We are grateful to Dr. H. Narimatsu and T. Shikanai (National Institute of Advanced Industrial Science and Technology, Japan) as well as Dr. N. Okino and Dr. Y. Kakuta (Kyushu University, Japan) for their valuable suggestions and technical support. This work is partially supported by the Grant-in-Aid for Scientific Research B (19380061 and 15H04488) (to M.I.) and Young Scientists (B) (15K18868) (to Y.H.) from the Ministry of Education, Culture, Sports, Science, and Technology of the Japanese Government.
PY - 2016
Y1 - 2016
N2 - Klotho (KL) family proteins share one or two glycoside hydrolase (GH) motifs homologous to GH family 1. However, the biological significance of GH motifs in KL family proteins remains elusive. We describe here that KL-related protein (KLrP), which is composed of a single GH motif, is a cytosolic β-glucocerebrosidase (GCase, EC 3.2.1.145). We detected a neutral conduritol B epoxide (CBE)-insensitive glucosylceramide (GlcCer)-degrading activity in the cytosol fractions of human fibroblasts, rat brains, and zebrafish embryos. KL family proteins emerged as a potent candidate for the neutral GCase using a bioinformatics approach. Recombinant human KLrP, but not α-KL, β-KL, or KLPH, exhibited GCase activity with a neutral pH optimum in the presence of CBE. We solved the crystal structures of KLrP and a KLrP mutant (E165Q) in complex with glucose, which indicate that KLrP forms a (β/α)8TIM barrel structure with the double-displacement mechanism of the retaining β-glycosidase. Furthermore, knockdown of endogenous KLrP in CHOP cells using small interfering RNA (siRNA) decreased the CBE-insensitive neutral GCase activity and increased the cellular levels of GlcCer, which suggests that KLrP is involved in a novel GlcCer catabolism pathway. A KLrP D106N mutant was discovered in patients with severe Gaucher disease; however, this mutation did not affect the GCase activity of KLrP.
AB - Klotho (KL) family proteins share one or two glycoside hydrolase (GH) motifs homologous to GH family 1. However, the biological significance of GH motifs in KL family proteins remains elusive. We describe here that KL-related protein (KLrP), which is composed of a single GH motif, is a cytosolic β-glucocerebrosidase (GCase, EC 3.2.1.145). We detected a neutral conduritol B epoxide (CBE)-insensitive glucosylceramide (GlcCer)-degrading activity in the cytosol fractions of human fibroblasts, rat brains, and zebrafish embryos. KL family proteins emerged as a potent candidate for the neutral GCase using a bioinformatics approach. Recombinant human KLrP, but not α-KL, β-KL, or KLPH, exhibited GCase activity with a neutral pH optimum in the presence of CBE. We solved the crystal structures of KLrP and a KLrP mutant (E165Q) in complex with glucose, which indicate that KLrP forms a (β/α)8TIM barrel structure with the double-displacement mechanism of the retaining β-glycosidase. Furthermore, knockdown of endogenous KLrP in CHOP cells using small interfering RNA (siRNA) decreased the CBE-insensitive neutral GCase activity and increased the cellular levels of GlcCer, which suggests that KLrP is involved in a novel GlcCer catabolism pathway. A KLrP D106N mutant was discovered in patients with severe Gaucher disease; however, this mutation did not affect the GCase activity of KLrP.
UR - http://www.scopus.com/inward/record.url?scp=84962210561&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84962210561&partnerID=8YFLogxK
U2 - 10.1016/bs.vh.2016.02.011
DO - 10.1016/bs.vh.2016.02.011
M3 - Conference contribution
C2 - 27125736
AN - SCOPUS:84962210561
SN - 9780128048191
T3 - Vitamins and Hormones
SP - 1
EP - 16
BT - Klotho, 2016
A2 - Litwack, Gerald
PB - Academic Press Inc.
ER -
