Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Reexamination Certificate
1998-05-26
2003-09-30
Priebe, Scott D. (Department: 1636)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
C536S023100, C530S303000, C530S350000, C435S069100
Reexamination Certificate
active
06627746
ABSTRACT:
1. INTRODUCTION
The present invention relates to
C. elegans
insulin-like genes and methods for identifying insulin-like genes. The methods provide nucleotide sequences of
C. elegans
insulin-like genes, amino acid sequences of their encoded proteins, and derivatives (e.g., fragments) and analogs thereof. The invention further relates to fragments (and derivatives and analogs thereof) of insulin-like proteins which comprise one or more domains of an insulin-like protein. Antibodies to an insulin-like protein, and derivatives and analogs thereof, are provided. Methods of production of an insulin-like protein (e.g., by recombinant means), and derivatives and analogs thereof, are provided. Methods to identify the biological function of a
C. elegans
insulin-like gene are provided, including various methods for the functional modification (e.g., overexpression, underexpression, mutation, knock-out) of one gene, or of two or more genes simultaneously. Methods to identify a
C. elegans
gene which modifies the function of, and/or functions in a downstream pathway from, an insulin-like gene are provided.
2. BACKGROUND OF THE INVENTION
Citation of references herein shall not be construed as an admission that such references are prior art to the present invention.
2.1. The Insulin Superfamily
Insulin-like proteins are a large and widely-distributed group of structurally-related peptide hormones that have pivotal roles in controlling animal growth, development, reproduction, and metabolism (Blundell and Humbel, 1980, “Hormone families: pancreatic hormones and homologous growth factors”, Nature 287:781-787). Consequently, the insulin superfamily has become one of the most intensively investigated classes of peptide hormones. Such hormones have a vast array of uses including, for example, clinical applications in human disease, management of fish and livestock, and the control of agriculturally-important animal pests. At least five different subfamilies of insulin-like proteins have been identified in vertebrates, represented by insulin (Steiner et al., 1989, in
Endocrinology,
DeGroot, ed., Philadelphia, Saunders, pp. 1263-1289), insulin-like growth factor (IGF, previously termed somatomedin) (Humbel, 1990, “Insulin-like growth factors I and II”, Eur. J. Biochem. 190:445-462), relaxin (Schwabe and Bullesback, 1994, “Relaxin: structures, functions, promises, and nonevolution”, FASEB J. 8:1152-1160), relaxin-like factor (RLF, previously called Leydig cell-specific insulin-like peptide) (Adham al., 1993, “Cloning of a cDNA for a novel insulin-like peptide of the testicular Leydig cells”, J. Biol. Chem. 268:26668-26672; Ivell, 1997, “Biology of the relaxin-like factor (RLF)”, Reviews of Reproduction 2:133-138), and placentin (also known as early placenta insulin-like peptide, or ELIP) (Chassin et al., 1995, “Cloning of a new member of the insulin gene superfamily (INSL4) expressed in human placenta”, Genomics 29:465-470).
Insulin superfamily members in invertebrates have been less extensively analyzed than in vertebrates, but a number of different subgroups have been defined. Such subgroups include molluscan insulin-related peptides (MIP-I to MIP-VII) (Smit et al., 1988, “Growth-controlling molluscan neurons produce the precursor of an insulin-related peptide”, Nature 331:535-538; Smit et al., 1995, “Expression and characterization of molluscan insulin-related peptide VII from the mollusc
Lymnaea stagnalis
”, Neuroscience 70:589-596), the bombyxins of lepidoptera (originally referred to as prothoracicotropic hormone or PTTH) (Kondo et al., 1996, “Multiple gene copies for bombyxin, an insulin-related peptide of the silkmoth
Bombyx mori
: structural signs for gene rearrangement and duplication responsible for generation of multiple molecular forms of bombyxin”, J Mol. Biol. 259:926-937), and the locust insulin-related peptide (LIRP) (Lagueux et al., 1990, “cDNAs from neurosecretory cells of brains of
Locusta migratoria
(Insecta, Orthoptera) encoding a novel member of the superfamily of insulins”, Eur. J. Biochem. 187:249-254). Most recently, putative orthologs of both vertebrate insulin and IGF have been identified in a tunicate (McRory and Sherwood, 1997, “Ancient divergence of insulin and insulin-like growth factor”, DNA and Cell Biology 116:939-949). This is of significance since tunicates are thought to be the closest living invertebrate relative to the progenitor from which vertebrates evolved (Id.).
Comparison of the primary sequence of insulin superfamily peptides, cDNAs, and genes, as well as the overall conservation of functional and structural domains of insulin-like genes and proteins, lead to the conclusion that existing members of the insulin superfamily evolved from a common ancestral gene (Blundell and Humbel, 1980, Id.). From the extensive sequence divergence evident among known subfamilies of insulin-like proteins, it is assumed that this is an ancient family of regulatory hormones that evolved to control growth, reproduction and metabolism in early metazoans. However, the precise evolutionary origins of this important family remain unclear. Indeed, until now, no bona fide insulin-like proteins or genes had been identified in metazoan orders more primitive than insecta.
2.1.1. Common Structural Themes
There are common structural themes that unite the insulin superfamily of proteins. All insulin-like peptide hormones are synthesized in vivo as precursor proteins having structures that are variations of the structure schematically represented in FIG.
1
. Most precursor forms of the insulin superfamily can be divided into four domains, termed Pre, B, C, and A domains, extending in order from the N-terminus to the C-terminus of a precursor polypeptide (see FIG.
1
). Precursors of the IGF subfamily are distinguished by having two additional domains at the C-terminal end, termed D and E domains. The N-terminal Pre domain typically contains a hydrophobic signal sequence which directs secretion of the hormone from cells and is removed by the enzymatic action of a signal peptidase during transit into the endoplasmic reticulum (see the asterisk in FIG.
1
). Upon folding, the prohormone undergoes additional processing which, in most cases, involves proteolytic cleavage at two sites that excise the C peptide from the mature hormone (see the left-hand and middle arrows illustrated in FIG.
1
). These processing steps are mediated by prohormone convertases that cleave at specific positions next to basic residues in the C peptide sequence. As a result, most forms of mature insulin superfamily hormones consist of two polypeptide chains, the A and B peptides, which are covalently joined by disulfide linkages (S—S) between Cys residues (see S—S linkages illustrated in FIG.
1
). The precise arrangement of Cys residues and disulfide linkages, both between and within the A and B peptides, is highly characteristic of the insulin superfamily of hormones. Nearly all known insulin superfamily members contain six precisely-positioned Cys residues, two in the B chain and four in the A chain, which participate in the formation of three disulfide bonds. Two of these disulfide linkages covalently join the B and A chains (i.e., they form inter-chain bonds), whereas the third disulfide linkage occurs within the A peptide (i.e., as an intra-chain bond) and appears to stabilize a bend in the A chain fold.
The IGF subfamily of hormones has a unique processing pathway. In this subfamily, the connecting C peptide is not removed by processing of the prohormone. Instead, a single proteolytic cleavage event removes the C-terminal E domain (see the right-hand arrow illustrated in FIG.
1
). Consequently, mature hormones of the IGF subfamily contain a single polypeptide chain with contiguous B, C, A, and D domains. Despite this difference in proteolytic processing, the disulfide bonding pattern between Cys residues in the IGF subfamily is identical to that of other superfamily members.
In summary,
FIG. 1
illustrates the structural organization of precursor forms of the insulin superfamily of hormones. T
Buchman Andrew Roy
Doberstein Stephen Kohl
Ferguson Kimberly Carr
Homburger Sheila Akiko
Platt Darren Mark
Exelixis Inc.
Kaushal Sumesh
Pennie & Edmonds LLP
Priebe Scott D.
LandOfFree
Nucleic acids and proteins of C. elegans insulin-like genes... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Nucleic acids and proteins of C. elegans insulin-like genes..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Nucleic acids and proteins of C. elegans insulin-like genes... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3112909