OBJECTIVES: Protein kinase C(PKC), a calcium and phospholipid dependent enzyme, is activated by lead in vitro at picomolar concentrations. However, the effect of lead on PKC has never been studied in a human population. The purpose of the study was to evaluate whether lead exposure was associated with PKC mediated-phosphorylation in erythrocytes among lead workers. METHODS: Two hundred and twelve lead workers were studied. To determine the levels of phosphorylation in vivo, an in vitro back phosphorylation technique was used by adding PKC and gamma-32P to preparations of erythrocyte membranes. We measured back phosphorylations of erythrocyte membrane proteins, spectrin, and 52 kDa and 48 kDa, as an indirect measure of PKC activation in vivo. RESULTS: The mean(SD) age and exposure duration was 39.1(10.0) years and 8.1(6.5) years, respectively. Tibial lead ranged from 0.8 to 290.8 microgram Pb/g bone mineral with a mean(SD) of 34.4(35.2) microgram Pb/g bone mineral. The means(SD) of back phosphorylation levels of the three proteins were 540.7(304.1), 198.6(78.2), and 247.7(83.3) photostimulated luminescence units(PSL), respectively, by phosphoimager. After adjustment for potential confounding factors, tibial lead and exposure duration were significantly and inversely associated with back phosphorylation levels. One unit of increase in tibial lead(1 microgram Pb/g bone mineral) is associated with a decline in spectrin, band 4.9 52 kDa, and band 4.9 48 kDa back phosphorylation levels by 1.4(P<0.05), 0.34(P<0.05), and 0.47(P<0.01), respectively. However, there were no associations between the back phosphorylation levels and either blood lead or ZPP levels. CONCLUSIONS: These findings suggest that the PKC activity in erythrocytes is increased by chronic lead exposure and that erythrocyte membrane protein phosphorylation may be a biomarker of lead exposure.
Calcium ; Erythrocyte Membrane ; Erythrocytes* ; Humans ; Luminescence ; Phosphorylation ; Protein Kinase C* ; Protein Kinases* ; Spectrin

Hereditary spherocytosis (HS) is a common inherited erythrocyte membrane disorder characterized by chronic hemolytic anemia. Clinical manifestations and biochemical abnormalities of HS are heterogeneous. In this study, we investigated erythrocyte membrane protein defects in 27 Korean HS cases. Utilizing both the Fairbanks system and the Laemmli system, sodium dodecyl sulfate polyacrylamide gel electrophoresis of erythrocyte membrane proteins was performed. Proteins were stained with Coomassie brilliant blue and gels were scanned using a densitometer. We detected spectrin deficiency in 7.4% of cases (2/27), ankyrin deficiency in 29.6% (8/27), combined spectrin and ankyrin deficiency in 3.7% (1/27), band 3 deficiency in 11.1% (3/27) and protein 4.2 deficiency in 14.8% (4/27). Membrane protein deficiencies were not observed in nine cases (33.3%, 9/27). Members of two of seven families tested showed the same protein defects as the proband. Ankyrin deficiency alone and combined with spectrin deficiency accounted for 33.3% of cases (9/27), and they were the most common biochemical defects in Korean HS cases. Protein 4.2 deficiency caused HS more frequently in Koreans than in Caucasians.
Ankyrins/analysis* ; Band 3 Protein/analysis* ; Erythrocyte Membrane/chemistry* ; Human ; Korea ; Spectrin/analysis* ; Spherocytosis, Hereditary/blood*

Hereditary spherocytosis (HS) is a common inherited erythrocyte membrane disorder characterized by chronic hemolytic anemia. Clinical manifestations and biochemical abnormalities of HS are heterogeneous. In this study, we investigated erythrocyte membrane protein defects in 27 Korean HS cases. Utilizing both the Fairbanks system and the Laemmli system, sodium dodecyl sulfate polyacrylamide gel electrophoresis of erythrocyte membrane proteins was performed. Proteins were stained with Coomassie brilliant blue and gels were scanned using a densitometer. We detected spectrin deficiency in 7.4% of cases (2/27), ankyrin deficiency in 29.6% (8/27), combined spectrin and ankyrin deficiency in 3.7% (1/27), band 3 deficiency in 11.1% (3/27) and protein 4.2 deficiency in 14.8% (4/27). Membrane protein deficiencies were not observed in nine cases (33.3%, 9/27). Members of two of seven families tested showed the same protein defects as the proband. Ankyrin deficiency alone and combined with spectrin deficiency accounted for 33.3% of cases (9/27), and they were the most common biochemical defects in Korean HS cases. Protein 4.2 deficiency caused HS more frequently in Koreans than in Caucasians.
Ankyrins/analysis* ; Band 3 Protein/analysis* ; Erythrocyte Membrane/chemistry* ; Human ; Korea ; Spectrin/analysis* ; Spherocytosis, Hereditary/blood*

OBJECTIVE: To investigate the molecular mechanism of the disease based on the clinical characterization and genetic mutation analysis in a family with hereditary spherocytosis. METHODS: The proband with jaundice and anemia was referred to Yidu Central Hospital of Weifang in May 2021. Peripheral blood samples were collected from six members of the family. Second-generation sequencing was used to screen the pathological mutations, and the clinically significant variant sites were selected. Then the relevant databases were used to analyze the variant sites, and RT-qPCR was used to detect the relative mRNA levels of candidate gene. The structure and function of SPTB protein were analyzed by UniProt and SMART databases. RESULTS: We infer that the SPTB gene copy number variation (CNV) deletion was co-segregated with the phenotype of the patients in this family based on the results of second-generation sequencing (about 700 target genes). The UCSC Genome Browser demonstrated that the deleted region was mainly located in exon2-3 of SPTB gene. The results of RT-qPCR showed that the relative SPTB mRNA levels of all patients were lower than the healthy control. UniProt and SMART databases analysis showed that SPTB protein without CH1 and CH2 domains could not bind to erythrocyte membrane actin. CONCLUSION The CNV deletion of SPTB gene may be the reason for the hereditary spherocytosis in this family.
Humans ; DNA Copy Number Variations ; East Asian People ; Mutation ; Pedigree ; Spectrin/genetics* ; Spherocytosis, Hereditary/diagnosis*

This study analyzed the clinical features of 5 children with hereditary spherocytosis (HS) and the characteristics of ANK1 and SPTB gene mutations. All 5 children were confirmed with HS by peripheral blood genetic detection. Anemia, jaundice and splenomegaly were observed in all 5 children. Three children had an increase in erythrocyte osmotic fragility. All 5 children had negative results of the Coombs test, glucose 6 phosphate dehydrogenase test, sucrose hemolysis test, acidified-serum hemolysis test and thalassemia gene test. Peripheral blood smear showed an increase in spherocyte count in one child. High-throughput sequencing revealed ANK1 gene mutations in patients 1 to 3, namely c.3398(exon29)delA, c.4306C>T and c.957(exon9)_c.961(exon9)delAATCT, among which c.3398(exon29)delA had not been reported before. Patient 4 had c.318delGExon3 mutation in the SPTB gene. Patient 5 had mutations in the SPTB and SLC4A1 genes, among which c.3484delC in the SPTB gene was a spontaneous mutation; the mutation site of the SLCA4A1 gene was inherited from the father and was a non-pathogenic gene. This study suggests that anemia, jaundice and splenomegaly are major clinical manifestations of HS children. Most children with HS do not have the typical spherocytic changes. Genetic detection may help with the accurate diagnosis of HS.
Ankyrins ; genetics ; High-Throughput Nucleotide Sequencing ; Humans ; Mutation ; Spectrin ; genetics ; Spherocytosis, Hereditary ; genetics

The kinesin proteins (KIFs) make up a large superfamily of molecular motors that transport cargo such as vesicles, protein complexes, and organelles. KIF5 is a heterotetrameric motor that conveys vesicles and plays an important role in neuronal function. Here, we used the yeast two-hybrid system to identify the neuronal protein (s) that interacts with the tail region of KIF5 and found a specific interaction with betaIII spectrin. The amino acid residues between 1394 and 1774 of betaIII spectrin were required for the interaction with KIF5C. betaIII spectrin also bound to the tail region of neuronal KIF5A and ubiquitous KIF5B but not to other kinesin family members in the yeast two-hybrid assay. In addition, these proteins showed specific interactions, confirmed by GST pull-down assay and co-immunoprecipitation. betaIII spectrin interacted with GST-KIF5 fusion proteins, but not with GST alone. An antibody to betaIII spectrin specifically co-immunoprecipitated KIF5s associated with betaIII spectrin from mouse brain extracts. These results suggest that KIF5 motor proteins transport vesicles or organelles that are coated with betaIII spectrin.
Animals ; Brain ; Humans ; Immunoprecipitation ; Kinesin* ; Mice ; Microtubules ; Neurons ; Organelles ; Spectrin* ; Transport Vesicles ; Two-Hybrid System Techniques

OBJECTIVE: To analyze the clinical characteristics and spectrum of SPTB gene variants among 16 Chinese children with Hereditary spherocytosis (HS) and explore their genotype-phenotype correlation. METHODS: Sixteen children who were diagnosed with HS at the Affiliated Hospital of Capital Institute of Pediatrics from November 2018 to July 2022 were selected as the research subjects. Genetic testing was carried out by whole exome sequencing. Candidate variants were verified by Sanger sequencing and subjected to bioinformatic analysis and prediction of 3D structure of the protein. Correlation between the SPTB genotypes and clinical phenotypes was analyzed using Chi-squared test. RESULTS: The male-to-female ratio of the HS patients was 6 : 10, with the median age being 7-year-and-10-month. Clinical features of the patients have included anemia, reticulocytosis and gradual onset of splenomegaly. Mild, moderate and severe anemia have respectively occurred in 56.25% (9/16), 31.25% (5/16) and 12.50% (2/16) of the patients. SPTB gene variants were detected in all patients, among which 10 were unreported previously and 7 were de novo in origin. Loss of function (LOF) variants accounted for 93.75% (15/16). Only one missense variant was detected. Eleven, 4 and 1 of the variants had occurred in the repeat domain, CH1 domain, and dimerization domain, respectively. There was no significant correlation between the type or domain of the SPTB gene variants with the clinical features such as severity of anemia (x² = 3.345, P > 0.05). All of the variants were predicted to be pathogenic or likely pathogenic based on the guidelines from the American College of Medical Genetics and Genomics. CONCLUSION Mild to moderate anemia are predominant clinical features of the HS children harboring a SPTB gene variant, for which LOF variants are the main mutational type. The clinical feature of HS is unaffected by the type of the variants.
Child ; Female ; Humans ; Male ; Computational Biology ; Genetic Testing ; Genomics ; Genotype ; Spherocytosis, Hereditary/genetics* ; East Asian People/genetics* ; Spectrin/genetics*

Adult ; Female ; Genetic Predisposition to Disease ; Humans ; Mutation, Missense ; genetics ; Spectrin ; genetics ; Spinocerebellar Ataxias ; etiology ; genetics ; Young Adult

Hereditary spherocytosis is a hemolytic anemia caused by erythrocyte membrane deficiencies that lead to membrane destabilization and vesiculation. Abnormal spherocytes are trapped and destroyed in the spleen. Mutations in several genes, SPTA1, SPTB, ANK1, SLCA1 and EPB42 cause alpha-spectrin, beta-spectrin, ankyrin, band 3 or protein 4.2 protein deficiencies, respectively. The clinical severity ranged from asymptomatic to severe hemolytic anemia requiring erythrocyte transfusion. Common complications are cholelithiasis, hemolytic episodes and aplastic crises. Till now, splenectomy is considered as only curative method in this genetic disorder. However, in the future, molecular analysis will make elucidate the genotype-phenotype interactions and can innovate to modify treatment strategies.
Anemia, Hemolytic ; Ankyrins ; Cholelithiasis ; Erythrocyte Membrane ; Erythrocyte Transfusion ; Erythrocytes ; Membranes ; Protein Deficiency ; Spectrin ; Spherocytes ; Spherocytosis, Hereditary ; Spleen ; Splenectomy

Band 3, the predominant 95,000 dalton anion transport protein, is the major intrinsic glycoprotein of the human erythrocyte membrane. This anion carrier exists as a dimer and binds the cytoskeletons such as spectrin, ankyrin and actin. And the liposomes are vesicular structures which form spontaneously upon hydration of phospholipids. These artificial lipid vesicles have been investigated as model of the biological membranes and as a mean of improving the delivery of nucleic acids, drugs, proteins and biological substances to specific target tissues and cells. In this study, we were purified Band 3 from the human erythrocyte membrane (ghost) was prepared by hemolysis of intact human erythrocyte with weak alkali-hypotonic solution. Band 6 was removed from ghost by extracting with solution of an ionic strength of 0.15. Band 3 and Band 4 were solubilized selectively by extracting Band 6-depleted ghosts with Triton X-100 under nondenaturing conditions. Band 3 was then purified from Triton X-100 extract treated with p-chloromercuribenzoate by sucrose density gradient ultracentrifugation. This purified Band 3 was incorporated into liposomes prepared by reverse-phase evaporation. Phosphatidyl L-serine and cholesterol (1:1 molar ratio) were dissolved in chloroform and the chloroform was removed by rotator evaporation under reduced pressure. Band 3 solution without Triton X-100 was introduced into a mixture of lipids and diethylether. Diethylether was subsequently removed by evaporation. This purified Band 3 and its incorporation into liposomes were confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.
Actins ; Ankyrins ; Chloroform ; Cholesterol ; Cytoskeleton ; Electrophoresis ; Erythrocyte Membrane* ; Erythrocytes* ; Glycoproteins ; Hemolysis ; Humans* ; Liposomes* ; Membranes ; Molar ; Nucleic Acids ; Octoxynol ; Osmolar Concentration ; Phospholipids ; Serine ; Sodium ; Spectrin ; Sucrose ; Ultracentrifugation