Retina International's Scientific Newsletter

	Retina International's Scientific Newsletter
Editor's Notes from literature on Prenyl Transferase (GGTase, FTase)

Recent update from: 19.12.1999

FTase, farnesyl

Notes

Comprised of two polypeptides: alpha and beta subunit
Modifies proteins terminating in CAAX
Most important determinant is the Cys at fourth position from C-terminus
Second important is the X at C-terminus with Met, Ser as FTase signal
C-terminal residue directs attached isoprenoid
Mg²⁺ and Zn²⁺ are required for catalysis
Mg²⁺ for binding the PP-moiety of the isoprenoid
Zn²⁺ catalytic component of the enzyme = Zinc metalloenzyme
Soluble protein

Species:

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE: 48 kDa, 46 kDa
	calculated:

Reference: (1)

GGtaseI, geranylgeranyl

Notes

GGtase I recognizes CAAX when X=Leu
Requires Zn²⁺ for catalytic activity
2 proteins, alpha identical to alpha-FTase
GGTase I can prenylate some Ftase substrates
Soluble protein

Species:

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE: 48 kDa, 43 kDa
	calculated:

Reference: (1)

GGtaseI, geranylgeranyl

Notes

CAAX target sequence for GGtase I
Targets: GNG, Ras related proteins Rac 1,2, Rap 1A/1B
Mg²⁺, Zn²⁺ dependent
alpha subunit is identical to FTase alpha subunit

Species:

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE: 48 kDa, 43 kDa
	calculated:

Reference: (6)

GGtaseII, Rab geranyl

Notes

GGtase II recognizes CXC- and CC-motif for exclusive geranylation of up to 2 Cys
Requires Zn²⁺ for catalytic activity
Soluble protein
2 components, A = REP1, B = GGTase dimer
Component A recognizes substrate
Substrate: Rab

Species:

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE: 60 kDa, 38 kDa
	calculated:

Reference: (1)

GGtaseII, Rab geranyl

Notes

Copurifies in the early isolation steps with component A as a complex of 350 kDa
Elutes on a high salt column as 100 kDa complex
Recognizes target not only by the C-terminus
Requires additional element that is shared by other Rabs

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (3)

RABGGTA, Rab geranyl a

Notes

91% identity to rat
Localization by FISH
Arranged in tadem (head to tail) with transglutaminase
cis-acting factors for cell-type specific transcription within the transcribed region of an unrelated gene

Species: Homo sapiens

See also:

Chromosomal localisation	in man: 14q11.2
	in mouse:

Gene Data

Exons:

Primers: Long-PCR primer

Protein Data

Aminoacids: 567 AA

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (5)

GGtaseI, Rab geranyl a

Notes

Yeast counterpart: CDC43

Species: Rattus norvegicus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids: 377 AA

Molecularweight	on SDS-PAGE:
	calculated: 42.5 kDa

Reference: (6)

GGtaseII, Rab geranyl b

Notes

Heterodimer of 90 kDa consisting of two subunits of 60 and 38 kDa
Activity in a 330 kDa protein complex of two fractions component A and B
Component seperation on salt concentrations above 200 nM
Red A Dyematrix column eluted with 2 M NaCl purifies component A from B

Species: Bos taurus

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (4)

RABGGTB, Rab geranyl b

Notes

95% identity to rat
Localization by FISH

Species: Homo sapiens

See also:

Chromosomal localisation	in man: 1p31
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids: 331 AA

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (5)

GGtaseII, Rab geranyl b

Notes

alpha-beta dimer
Needs acessory component A
Identity to rat: 82.4% at nucleotide level, 91.1% at AA level
Transfers GG from GG PP
Similarity to FTase beta
Ubiquitous expression

Species: Homo sapiens

See also:

Chromosomal localisation	in man: 1p31-p22
	in mouse:

Gene Data

mRNA: 1.5 + 1.9 kb

Exons:

Primers:

Protein Data

Aminoacids:

Molecularweight	on SDS-PAGE:
	calculated:

Reference: (2)

GGtaseI, Rab geranyl b

Notes

Yeast counterpart: CDC43

Species: Homo sapiens

See also:

Chromosomal localisation	in man:
	in mouse:

Gene Data

Exons:

Primers:

Protein Data

Aminoacids: 377 AA

Molecularweight	on SDS-PAGE:
	calculated: 42.4 kDa

Reference: (6)

References:

1. Casey, P.J., Moomaw, J.F., Zhang, F.L., Higgins, J.B., and Thissen, J.A. Prenylation and G protein signaling. 1994; Recent.Prog.Horm.Res. 49: 215 - 238.
Goto Top

2. Sanders, R., Islam, K.B., Betz, R., Larsson, C., and Smith, C.I. A human homologue of the rat rab geranylgeranyl transferase beta subunit on chromosome 1p22-p31. 1996; Genomics. 35: 633 - 635.
Goto Top

3. Seabra, M.C., Brown, M.S., Slaughter, C.A., Sudhof, T.C., and Goldstein, J.L. Purification of component A of Rab geranylgeranyl transferase: possible identity with the choroideremia gene product. 1992; Cell. 70: 1049 - 1057.
Goto Top Link to PudMed

4. Seabra, M.C., Goldstein, J.L., Sudhof, T.C., and Brown, M.S. Rab geranylgeranyl transferase. A multisubunit enzyme that prenylates GTP-binding proteins terminating in Cys-X-Cys or Cys-Cys. 1992; J.Biol.Chem. 267: 14497 - 14503.
Goto Top Link to PudMed

5. Van Bokhoven, H., Rawson, R.B., Merkx, G.F., Cremers, F.P., and Seabra, M.C. cDNA cloning and chromosomal localization of the genes encoding the alpha- and beta-subunits of human Rab geranylgeranyl transferase: the 3' end of the alpha-subunit gene overlaps with the transglutaminase 1 gene promoter. 1996; Genomics. 38: 133 - 140.
Goto Top Link to PudMed

6. Zhang, F.L., Diehl, R.E., Kohl, N.E., Gibbs, J.B., Giros, B., Casey, P.J., and Omer, C.A. cDNA cloning and expression of rat and human protein geranylgeranyltransferase type-I. 1994; J.Biol.Chem. 269: 3175 - 3180.
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