Retina International's Scientific Newsletter

	Retina International's Scientific Newsletter
Editor's Notes from literature on Phosducin (PDC)

Recent update from: 19.12.1999

PDC, MEKA

Notes

Binds GNB-GNG

Species:

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (13)

Phd

Notes

Selectively binds GNB/G
Interacts to 26S proteasome complex via SUG1 orthologue

Species: Bos taurus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (20)

Phd

Notes

First 63 AA are required for inhibition of GNB/G
Mutation Trp 29 Val severely impairs inhibition

Species: Bos taurus

See also: GNT

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (17)

Phd

Notes

Blocks activation of several classes of G-proteins
Phosphorylated by PKA in the dark
No interaction of Phd and GNAT
[Phd] = [GNAT]
Phosphorylated in and off complex with GNB/G
Phd blocks GNAT binding to RHO in the presence of stoichiometric GNB/G amounts

Species: Bos taurus

See also: GNT

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated: 28 kDa

Reference: (18)

PDC

Notes

Phosphorylated by PKA, dephosphorylated by PP2A
Wrapped around one side and the top of GNB/GNG
PDC covers the pocket of GNB/G where farnesyl modification is placed during cytosolic phase
Farnesyl is necessary for membrane association which is necessary for GNAT-GNB/G interaction
No interaction of GNG and PDC

Species: Bos taurus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (12)

Phd

Notes

Phosphorylation site at Ser73
Putative N-glycosylation at 152-154

Species: Bos taurus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

cDNA:

Exons:

Primers:

Protein Data

Aminoacids: 246 AA

Molecularweight	on SDS-PAGE:
	calculated: 28176

Reference: (3)

pdc

Notes

1.5-fold increased expression in pre-degenerate affected retina
Retina-specific transcript
Conserved residue Ser-73 as phosphorylation site of PRKA

Species: Canis familiaris

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

mRNA: 1.9 kb, 3.5 kb

Exons:

Primers:

Protein Data

Aminoacids: 245

Molecularweight	on SDS-PAGE:
	calculated: 28209 Da

Reference: (19)

PDC, MEKA

Notes

2 PCE-1 elements
18 kb genomic DNA
No CAAT-, GC-, TATA-box

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

cDNA: 3,5 kb

Exons: 4

Primers:

Protein Data

Aminoacids: 246 AA

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (8)

PDC, MEKA

Notes

Principle watersoluble phosphoprotein of photoreceptor cells in rods and cones
Mediates phototransduction by interacting with GNB/G
Virtually identical to the G-protein Inhibitor Protein (GIP) in brain
18 kb genomic length
Splicing follows standard
Phosphorylated by PKA
P-PDC looses affinity to GNB/G
Undergoes alternative splicing
No TATA-, GC-, or CAAT-box

Species: Homo sapiens

See also:

Chromosomal localisation	in man: 1q25-32
	in mouse:

Gene Data

cDNA:

Exons: 4

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (2)

PDC, MEKA

Notes

Somatic Cell Hybridization and FISH

Species: Homo sapiens

See also:

Chromosomal localisation	in man: 1q25-q32.1
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (16)

PDC, MEKA

Notes

FISH technique with PDC-PCR-fragment

Species: Homo sapiens

See also:

Chromosomal localisation	in man: 1q25-q31.1
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (10)

PDC, MEKA

Notes

Polymorphisms in the 5' UTR detected by SSCP
PDC1: -653 Ins g; AGA 51%, AA 49%; PIC: 0.5
PDC2: -488 del t; ATC 87%, AC 13%; PIC: 0.23
PDC3: -1083 t-g; T 74%, G 26%; PIC: 0.39

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers: Flanking polymorphisms

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (15)

Pd, MEKA

Notes

45 controls
83 patients
heterozygous Gly 178 Arg in a USH2 patient
heterozygous Asp 174 Lys in a AZOOR patient
3 non-coding variants in 20.8% of American and 2.4% Japanese controls
Mutations seem not to be causative

Species: Homo sapiens

See also:

Chromosomal localisation	in man: 1q25-32.1
	in mouse:

Gene Data

Exons:

Primers: Exons 2 - 4

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (4)

PDC, MEKA

Notes

Phosphorylation site at Ser73
Putative N-glycosylation at 152-154

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

cDNA:

Exons: 4

Primers:

Protein Data

Aminoacids: 246 AA

Molecularweight	on SDS-PAGE:
	calculated: 28246

Reference: (3)

Pd, MEKA

Notes

close to Lamb2, 10 cM from Sag
exhibits light dependent phosphorylation
Here called Rpr-1
Human LAMB2 is on 1q25-q31

Species: Mus musculus

See also:

Chromosomal localisation	in man:
	in mouse: 1

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (9)

PDC, MEKA

Notes

Knock out =>
Primary phototransduction unaltered
Time course of a-wave unaltered
I50 = normal
Recovery phase normal
b-wave reduced after increased dark adaptation
Reduced Vmax of ERG without less sensitivity
Degeneration in an age related manner
Response recoveries in dark are at a lower plateau

Species: Mus musculus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (11)

Pd, MEKA

Notes

phosphorylated by PKA at consensus RKXS at Ser71
inhibits GTPase activity of GNAT
photoreceptor and pineal gland specific, low levels in other tissues
no CAAT-, TATA-, or GC-Box
12 bp element and PCE1
1 TATA- and 2 CAAT-like
Mouse DNA identity to man (78%) - rat (87%) - bovine (74%)
Mouse protein identity to man/bovine (88%) - rat (95%)
15 kb genomic DNA
Splice sites follow standard
Watersoluble

Species: Mus musculus

See also: GNT

Chromosomal localisation	in man:
	in mouse: 1

Gene Data

mRNA:

Exons: 4

Primers:

Protein Data

Aminoacids: 244 AA

Molecularweight	on SDS-PAGE: 33 kDa
	calculated:

Reference: (1)

PDC

Notes

Cytosolic
High affinity interactions by C-terminal fragment of residues 215-232
Tyr 224 Ala reduces functional activity to N-terminus activity
Phosphorylated by PRKA
High concentrations in retina and pineal, less in other tissues

Species: recombinant

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (7)

Phd

Notes

After phosphorylation Phd binding to GNB/G is abolished
Binds GNB/G (affinity 55 nM) and GNAT (affinity 110 nM
Does not inhibit GTP hydrolytic activity of GNAT
GDP release is decreased by Phd by blocking GNB/G
Additive mode of inhibition via GNB/G and GNAT
Phosphorylation causes a major alteration of Phd structure

Species: Recombinant

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (5)

Phd, brain

Notes

GIP possibly identical to phosducin
PDC inhibits G_s, G_i, G₀, and G_a0 at a ratio of PDC:G 2:1
RAl PDC traps GNB/G
PDC is phosphorylated and GNB/G binding is inhibited by PKA

Species: Bos taurus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons: 4

Primers: ORF in one piece

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated: 33000

Reference: (6)

PDC, MEKA, pineal

Notes

Phosphorylation site at Ser73
Putative N-glycosylation at 152-154

Species: Rattus norvegicus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

mRNA: ca. 1300 nt

Exons:

Primers:

Protein Data

Aminoacids: 245 AA

Molecularweight	on SDS-PAGE:
	calculated: 28246

Reference: (3)

PDC, MEKA, retinal

Notes

Phosphorylation site at Ser73
Putative N-glycosylation at 152-154
AA sequence nearly identical in retina and pineal
87% nucleotide identity among human, rat, and bovine
88% aa identity to human

Species: Rattus norvegicus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

mRNA: ca. 1300 nt

Exons:

Primers:

Protein Data

Aminoacids: 245 AA

Molecularweight	on SDS-PAGE:
	calculated: 28143

Reference: (3)

Phd, rods

Notes

Interaction only with GNAT dissociated from membranes
Failed to dissociate membrane bound GNT
Blocks rebinding of GNAT to the ROS membrane
No cGMP hydolysis activity
Inhibits ADP-ribosylation of GNAT
Unable to recycle => down regulation of cascade
Negative regulator
Forms a tight complex, not crosslinked, with GNB/G at AA 78-88
Light-dependent phosphorylated at Ser-73
Dephosphorylated by PP2A on illumination
Phosphoprotein

Species: Bos taurus

See also: GNT

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated: 28 kDa

Reference: (14)

References:

1. Abe, T., Kikuchi, T., Chang, T., and Shinohara, T. The sequence of the mouse phosducin-encoding gene and its 5'-flanking region. 1993; Gene. 133: 179 - 186.
Goto Top

2. Abe, T., Kikuchi, T., and Shinohara, T. The Sequence of the Human Phosducin Gene (Pdc) and Its 5'-Flanking Region. 1994; Genomics. 19: 369 - 372.
Goto Top

3. Abe, T., Nakabayashi, H., Tamada, H., Takagi, T., Sakuragi, S., Yamaki, K., and Shinohara, T. Analysis of the human, bovine and rat 33-kDa proteins and cDNA in retina and pineal gland. 1990; Gene. 91: 209 - 215.
Goto Top

4. Ara Iwata, F., Jacobson, S.G., Gass, J.D., Hotta, Y., Fujiki, K., Hayakawa, M., and Inana, G. Analysis of phosducin as a candidate gene for retinopathies. 1996; Ophthalmic Genet. 17: 3 - 14.
Goto Top Link to PudMed

5. Bauer, P.H., Bluml, K., Schroder, S., Hegler, J., Dees, C., and Lohse, M.J. Interactions of phosducin with the subunits of G-proteins. Binding to the alpha as well as the betagamma subunits. 1998; J.Biol.Chem. 273: 9465 - 9471.
Goto Top Link to PudMed

6. Bauer, P.H., Muller, S., Puzicha, M., Pippig, S., Obermaier, B., Helmreich, E.J., and Lohse, M.J. Phosducin is a protein kinase A-regulated G-protein regulator. 1992; Brain.Dev. 358: 73 - 76.
Goto Top

7. Bluml, K., Schnepp, W., Schroder, S., Beyermann, M., Macias, M., Oschkinat, H., and Lohse, M.J. A small region in phosducin inhibits G-protein betagamma-subunit function. 1997; EMBO J. 16: 4908 - 4915.
Goto Top

8. Chang, M., Abe, T., Kikuchi, T., and Shinohara, T. The sequence of the human phosducin gene and its 5'-flanking region. 1994; Invest.Ophthalmol.Vis.Sci. 35 (Suppl.): 1718
Goto Top

9. Danciger, M., Kozak, C.A., Abe, T., Shinohara, T., and Farber, D.B. The gene for retinal rod 33-kDa protein is on mouse chromosome 1, near Lamb2. 1991; Cytogenet.Cell Genet. 56: 202 - 205.
Goto Top

10. Ding, C., Li, X., Griffin, C.A., Jabs, E.W., Hawkins, A.L., and Levine, M.A. The gene for human phosducin (PDC), a soluble protein that binds G-protein beta gamma dimers, maps to 1q25-q31.1. 1993; Genomics. 18: 457 - 459.
Goto Top

11. Hamasaki, D.I., Perez, J., Abe, T., Kikuchi, T., and Shinohara, T. Retinal physiology and morphology in a transgenic mouse with a mutant phosducin gene. 1995; Invest.Ophthalmol.Vis.Sci. 36: S641
Goto Top

12. Ho, Y.-K., Loew, A., Blundell, T., and Bax, B. Phosducin Induces A Structural Shift On Transducin ?? That Internalizes The G Subunit Farnesyl Group. 1998; Invest.Ophthalmol.Vis.Sci. 39: S442
Goto Top

13. Lee, R.H., Lieberman, B.S., and Lolley, R.N. A novel complex from bovine visual cells of a 33,000-dalton phosphoprotein with beta- and gamma-transducin: purification and subunit structure. 1987; Biochemistry. 26: 3983 - 3990.
Goto Top Link to PudMed

14. Lee, R.H., Ting, T.D., Lieberman, B.S., Tobias, D.E., Lolley, R.N., and Ho, Y.K. Regulation of retinal cGMP cascade by phosducin in bovine rod photoreceptor cells. Interaction of phosducin and transducin Regulation of retinal cGMP cascade by phosducin in bovine rod photoreceptor cells. Interaction of phosducin and transducin. 1992; J.Biol.Chem. 267: 25104 - 25112.
Goto Top Link to PudMed

15. Mansergh, F.C., Jordan, S.A., Farrar, G.J., Kumarsingh, R., Gal, A., Bhattacharya, S., and Humphries, P. Three sequence polymorphisms in the PDC gene. 1994; Hum.Mol.Genet. 3: 2077
Goto Top Link to PudMed

16. Sparkes, R.S., Lee, R.H., Shinohara, T., Craft, C.M., Kojis, T., Klisak, I., Heinzmann, C., and Bateman, J.B. Assignment of the phosducin (PDC) gene to human chromosome 1q25-1q32.1 by somatic cell hybridization and in situ hybridization. 1993; Genomics. 18: 426 - 428.
Goto Top Link to PudMed

17. Xu, J., Wu, D.Q., Slepak, V.Z., and Simon, M.I. The N terminus of phosducin is involved in binding of beta gamma subunits of G protein. 1995; Proc.Natl.Acad.Sci.U.S.A. 92: 2086 - 2090.
Goto Top

18. Yoshida, T., Willardson, B.M., Wilkins, J.F., Jensen, G.J., Thornton, B.D., and Bitensky, M.W. The phosphorylation state of phosducin determines its ability to block transducin subunit interactions and inhibit transducin binding to activated rhodopsin. 1994; J.Biol.Chem. 269: 24050 - 24057.
Goto Top

19. Zhang, Q., Acland, G.M., Parshall, C.J., Haskell, J., Ray, K., and Aguirre, G.D. Characterization of canine photoreceptor phosducin cDNA and identification of a sequence variant in dogs with photoreceptor dysplasia. 1998; Gene. 215: 231 - 239.
Goto Top Link to PudMed

20. Zhu, X. and Craft, C.M. Interaction of phosducin and phosducin isoforms with a 26S proteasomal subunit, SUG1. 1998; Mol.Vis. 4: 13
Goto Top Link to PudMed
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Contact the editor: irpamp@irpa.org	This site is maintained and edited by Dr. rer. medic. Markus Preising, Dipl.Biol. Molecular Genetics Laboratory Department of Paediatric Ophthalmology, Strabismology and Ophthalmogenetics University of Regensburg Head: Prof. Dr. med. Birgit Lorenz